On 21/02/2024 13:01, Paul wrote:
> On 2/21/2024 6:47 AM, SteveW wrote:
>> On 21/02/2024 05:48, Sid@home.com wrote:
>>> On Wed, 21 Feb 2024 03:26:37 +0000, John Rumm wrote:
>>>
>>>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>>>
>>>>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>>>>> associated voltage spikes etc.), so I decided to get a UPS to protect
>>>>> things.
>>>>>
>>>>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>>>>
>>>>> The next question is "How big a UPS do I need?"
>>>>>
>>>>> I went looking for advice on this, and found most said:
>>>>>
>>>>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating (90W)
>>>>> and the Monitor (78W) to get the max load (1018W) then multiply by 50%
>>>>> (some say 100%) to give some headroom.
>>>>> Some even pointed out that (e.g.) the PC PSU rating was its DC output,
>>>>> so its AC input would be even greater so...
>>>>
>>>> That all sounds a bit excessive...
>>>>
>>>> What graphics card is in the PC?
>>>>
>>>>> Things seemed to be getting completely out of hand, so I decided to
>>>>> measure, not calculate.
>>>>>
>>>>> I put those three items (PC, Monitor & NAS) on a separate supply
>>>>> circuit monitored by a power meter set to record max power draw in
>>>>> watts (VA would have been better, but that's what I had available).
>>>>>
>>>>> Ran things up.  Pulled video down from the NAS & ran it on the PC.  Ran
>>>>> up a few more apps at the same time - I did pretty much anything I
>>>>> could think of to max out the loading.
>>>>>
>>>>> Maximum recorded power demand 159W.
>>>>>
>>>>> The difference between the recommended calculated load and the measured
>>>>> load is so vast that I'm beginning to doubt myself.
>>>>
>>>> Even a fairly powerful PC is unlikely to draw more than 250W
>>>> continuously. Probably less than 100W most of the time. The other things
>>>> not much - unlikely to be more than 100W all together. (note that inrush
>>>> can be much higher - so turning kit on while running on battery can
>>>> glitch the output enough to drop a load or reboot a PC)
>>>>
>>>> So a 650VA UPS would likely be plenty, and leave some capacity to spare.
>>>> That kind of device is also fairly cheap.
>>>>
>>>> Having said that you often find that as the VA rating goes up, at some
>>>> point so does the battery capacity. So if you only have 500VA max load,
>>>> it can still be worth going from the (adequate) 600VA to the (overkill)
>>>> 1kVA to get the bigger batteries and double the run time.
>>>>
>>>> (I recently wanted one to hold up a micro form factor PC (fairly high
>>>> end i7 box - running accounting software in 4 VMs), a synology NAS, and
>>>> various bits of network kit including a 24 port PoE switch).
>>>>
>>>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
>>>> been plenty. However at half load the unit was only rated for about 6
>>>> mins. So going for the 1.2kVA version which has twice the battery size
>>>> gave plenty of time for the orderly shutdown of the NAS and all the VMs
>>>> if required. (in reality, according to actual load shown on the the
>>>> power meter on the UPS, it will likely get 60+ mins of runtime)
>>>>
>>>> Something else to consider when supporting multiple bits of kit is how
>>>> you will synch the shutdown of the attached loads. Most UPS devices have
>>>> a USB connection these days that lets you connect a single PC or other
>>>> device and monitor it. That also allows you to specify a charge
>>>> remaining threshold when the device should power down. That is easy with
>>>> just one PC.
>>>>
>>>> However it gets a bit more complicated with multiple devices. There is
>>>> an open source suite of software called NUT (Network UPS Tools), that
>>>> allows one device physically talking to the UPS to act as a server and
>>>> share information about the current power state with multiple clients. I
>>>> found the Synology box actually uses this for its default UPS monitoring
>>>> capability (although it does not seem to name it directly). That made it
>>>> easy to get a NUT client for the main windows machine running the
>>>> hypervisor, setup the NAS as the NUT server, and point the windows box
>>>> at that. That the whole lot can be gracefully shutdown in sequence, and
>>>> then finally switch off the UPS itself as well once the available
>>>> capacity falls below the desired capacity threshold.
>>>>
>>>> (on restoration of mains, everything is configured to come back up can
>>>> carry on were it left off)
>>>>
>>>>> I'm certainly not the first person to go down this route so...
>>>>> Comments please.
>>>>
>>>> I have an extension lead made up with exposed individual wires, so that
>>>> I can loop them through a clamp meter:
>>>>
>>>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_
>>> (Medium).jpg
>>>>
>>>> Makes a handy way to get a feel for the actual size of UPS required.
>>>
>>> Amazingly, I have never required a UPS over thirty years of computing.
>>
>> If you run a home server, you don't want to risk corruption of the storage array due to power cuts, brownouts or spikes, so a UPS is a very good idea. Also useful to avoid having to restart the server if you need to knock the power off for a few minutes during DIY.
>>
>> As we are switched over to digital telephony, a UPS to keep the phone working may become a good idea too.
>>
>
> You do NOT want to mess up RAID arrays, by doing dirty shutdowns.
> Yes, there are kinds of equipment you definitely want a UPS.
>
I dont run RAID for that reason.

I just have mirror disks, synched once a night.

RAID is not for backup, it is for high availability.
No domestic setup needs RAID.

....

>
> RAID arrays still need backups. And a UPS helps prevent them
> from becoming de-synchronized.
>
So whats the point of RAID?
In short its not a data protection strategy at all, its high
availability to data in a data centre

> I do not really know what keeps consumer SSDs alive on power failures.

They are not kept alive.
They shut down smoothly. Probably have big capacitors to flush writes to
the NVRAM if they detect power failure. I pull the plug on mine often,
without issue.

> It's supposed to be a "firmware scheme", but since they don't have
> advanced power fail detection (and a Supercap), it's not hardware
> that protects them against critical data loss. It's hard to imagine the
> flash has sufficient life for any sort of firmware scheme to make
> the device "reliable".

You appear to be babbling.

Flash doesn't need power to retain data, It will only cache data in RAM
for a short while before writing it, and the time to write it if
external power goes down is microseconds. It doesn't need a supercap. An
ordinary one will do. And it doesn't need 'advanced power fail
detection' a simple monitor of supply voltage on the far side of a diode
will serve to tell them they have lost external power and to flush all
caches to NVRAM now.

How do you *think* SSDS would work if you shutdown the computer they are
attached to? They don't have a 'shutdown' signal. They just get the
power removed. They presumably simply DO monitor supply voltages .

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 21/02/2024 13:17, Tim Lamb wrote:
> In message <ur4qvl$34q74$2@dont-email.me>, The Natural Philosopher
> <tnp@invalid.invalid> writes
>> On 21/02/2024 11:03, nothanks@aolbin.com wrote:
>>
>>> The simplest advice is to switch to a laptop with external display,
>>> keyboard and mouse. I did that a very long time ago and have never
>>> lost  data for any reason.
>>
>> I doubt I could fit 4TB disk into a laptop.
>> My main server died yesterday. It was my oldest and worst *86 machine,
>> so I popped its disks into my second worst *86 machine and rebooted.
>> Apart from it insisting on using a DHCP network address because the
>> ethernet came up as a different device, it was in fact a straight reboot.
>>
>> No data was lost.
>>
>> Unless you have a *very* busy machine, power loss wont corrupt your
>> disks.
>>
>> UPS is more about having internet  access during a power cut, for me.
>
> As it is now 62 years ago I can tell a tale about UPS. Final year
> apprentice, with a car! I was often sent to sites to stand by during
> testing of our electrical equipment.
> This occasion was the American Air Force. Communications set up with a
> specification of 10mS interruption of supply only. Our device was a
> transistor power supply for the windings of a permanently running
> battery fed alternator. Might have been 50 lead acid batteries in that
> room!
> The test failed miserably. Basically the winding inductance opposed the
> level of current change needed to maintain synchronous speed.
>
> The solution was to fit a massive flywheel:-)
>

I saw the same on the Decca Elizabethan used to test radar systems.
Before takeoff there was a massive whining under the floor 'what's
that? ' 'Its our rotary converter: powers everything in the racks off
the aircraft 48V' 'Why not use transistors?' 'because when the wheels go
up we are lucky to get 24V out of the batteries: the rotary converter
has enough spinning mass to keep it all stable'

--
It is the folly of too many to mistake the echo of a London coffee-house
for the voice of the kingdom.

Jonathan Swift

On 21/02/2024 03:26, John Rumm wrote:
> On 20/02/2024 20:46, Sam Plusnet wrote:
>> I put those three items (PC, Monitor & NAS) on a separate supply
>> circuit monitored by a power meter set to record max power draw in
>> watts (VA would have been better, but that's what I had available).
>>
>> Ran things up.  Pulled video down from the NAS & ran it on the PC.
>> Ran up a few more apps at the same time - I did pretty much anything I
>> could think of to max out the loading.
>>
>> Maximum recorded power demand 159W.
>>
>> The difference between the recommended calculated load and the
>> measured load is so vast that I'm beginning to doubt myself.
>
> Even a fairly powerful PC is unlikely to draw more than 250W
> continuously. Probably less than 100W most of the time. The other things
> not much - unlikely to be more than 100W all together. (note that inrush
> can be much higher - so turning kit on while running on battery can
> glitch the output enough to drop a load or reboot a PC)
>
> So a 650VA UPS would likely be plenty, and leave some capacity to spare.
> That kind of device is also fairly cheap.
>
> Having said that you often find that as the VA rating goes up, at some
> point so does the battery capacity. So if you only have 500VA max load,
> it can still be worth going from the (adequate) 600VA to the (overkill)
> 1kVA to get the bigger batteries and double the run time.
>
> (I recently wanted one to hold up a micro form factor PC (fairly high
> end i7 box - running accounting software in 4 VMs), a synology NAS, and
> various bits of network kit including a 24 port PoE switch).
>
> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
> been plenty. However at half load the unit was only rated for about 6
> mins. So going for the 1.2kVA version which has twice the battery size
> gave plenty of time for the orderly shutdown of the NAS and all the VMs
> if required. (in reality, according to actual load shown on the the
> power meter on the UPS, it will likely get 60+ mins of runtime)
>
> Something else to consider when supporting multiple bits of kit is how
> you will synch the shutdown of the attached loads. Most UPS devices have
> a USB connection these days that lets you connect a single PC or other
> device and monitor it. That also allows you to specify a charge
> remaining threshold when the device should power down. That is easy with
> just one PC.
>
> However it gets a bit more complicated with multiple devices. There is
> an open source suite of software called NUT (Network UPS Tools), that
> allows one device physically talking to the UPS to act as a server and
> share information about the current power state with multiple clients. I
> found the Synology box actually uses this for its default UPS monitoring
> capability (although it does not seem to name it directly). That made it
> easy to get a NUT client for the main windows machine running the
> hypervisor, setup the NAS as the NUT server, and point the windows box
> at that. That the whole lot can be gracefully shutdown in sequence, and
> then finally switch off the UPS itself as well once the available
> capacity falls below the desired capacity threshold.
>
> (on restoration of mains, everything is configured to come back up can
> carry on were it left off)
>
>> I'm certainly not the first person to go down this route so...
>> Comments please.
>
> I have an extension lead made up with exposed individual wires, so that
> I can loop them through a clamp meter:
>
> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_(Medium).jpg
>
> Makes a handy way to get a feel for the actual size of UPS required.

The one piece of advice that I would give you, from learning the hard
way, is when you receive the UPS, bite the bullet and actually make sure
it works while it's still in warranty, and do it at a time when you can
manage without the various computers, both when you are shutting them
down cleanly to allow the UPS to be interposed between the mains and the
computers, and when you simulate a loss of mains and hope that the UPS
will work.

My wife bought an expensive PC which came with a UPS - probably rated at
700 VA since that was a common size at the time.

We didn't test it at the time, and only got round to trying it a year or
so later, by which time its manufacturer's warranty had expired. Add it
was as dead as a dodo. Even after leaving the battery on charge for a
couple of days (vastly excess of what its battery should need), it would
not supply any power.

I took it out of the PC setup and tried it in isolation. It lit a 60 W
tungsten bulb for about 5 seconds. It lit a 7 W LED bulb (Philips Hue,
IIRC) for about 15 seconds. Powered by the mains, and connected to a PC
by mains and by its USB monitoring connection, with the PC running the
UPS's monitoring software, the UPS reported the battery state as
"excellent" but the UPS would not run off that battery.

This is something I have experienced in several situations. I have a
Samsung laptop and its battery is reported by Windows and by MX Linux
(booting off different HDDs) as 100% capacity while connected to the
mains PSU/charger, but as soon as I unplug the PSU, the laptop turns off
instantaneously.

It seems that laptops and UPSes can "see" their battery as holding a
full charge, but as soon as you remove the power input, the device stops
working, as if the battery is really as flat as a pancake.

IN my experience, don't trust the UPS hardware and software to tell the
truth - test it periodically by simulating a power cut.

And simulate the type of power cut that you typically get. It may be a
long power cut or it may be a series of brief 1-second cuts in rapid
succession. My Windows 7 PC seems to be fine with a single power cut
(whether brief or several hours) and will always boot fine afterwards.
But several 1-second cuts at 10-second intervals will knacker the HDD.
Not irreparably, but enough to require a very long file-system check
before it will start to boot.

On 21/02/2024 12:00, Jeff Gaines wrote:
> On 21/02/2024 in message <ur4o0v$33uk8$2@dont-email.me> SteveW wrote:
>
>>> I've always lived in rural areas with overhead cables so power cuts
>>> are frequent. I have it set up so as soon as mains power is lost the
>>> PC  shuts down, I don't expect it to run the PC in the event of a
>>> power cut.
>>
>> Do you actually have it set to shut the PC down immediately or with a
>> couple of minutes' delay? The latter would allow for times when the
>> power cuts out, but reconnects shortly after.
>
> The latter, hibernates after 3 minutes.
>

My NAS, PC and UPS talk to eachother via USB. Rather than setting a time
to run on battery power, I've set mine to shut down when there's 5%
charge remaining.

I only have a small UPS - the point being to let the PC and NAS shut
down gracefully avoiding any disk corruption, rather than to let me
carry on working during an extended power cut.

--
Reentrant

On 21/02/2024 14:12, The Natural Philosopher wrote:
> On 21/02/2024 13:01, Paul wrote:
>> On 2/21/2024 6:47 AM, SteveW wrote:
>>> On 21/02/2024 05:48, Sid@home.com wrote:
>>>> On Wed, 21 Feb 2024 03:26:37 +0000, John Rumm wrote:
>>>>
>>>>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>>>>
>>>>>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>>>>>> associated voltage spikes etc.), so I decided to get a UPS to protect
>>>>>> things.
>>>>>>
>>>>>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>>>>>
>>>>>> The next question is "How big a UPS do I need?"
>>>>>>
>>>>>> I went looking for advice on this, and found most said:
>>>>>>
>>>>>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating
>>>>>> (90W)
>>>>>> and the Monitor (78W) to get the max load (1018W) then multiply by
>>>>>> 50%
>>>>>> (some say 100%) to give some headroom.
>>>>>> Some even pointed out that (e.g.) the PC PSU rating was its DC
>>>>>> output,
>>>>>> so its AC input would be even greater so...
>>>>>
>>>>> That all sounds a bit excessive...
>>>>>
>>>>> What graphics card is in the PC?
>>>>>
>>>>>> Things seemed to be getting completely out of hand, so I decided to
>>>>>> measure, not calculate.
>>>>>>
>>>>>> I put those three items (PC, Monitor & NAS) on a separate supply
>>>>>> circuit monitored by a power meter set to record max power draw in
>>>>>> watts (VA would have been better, but that's what I had available).
>>>>>>
>>>>>> Ran things up.  Pulled video down from the NAS & ran it on the
>>>>>> PC.  Ran
>>>>>> up a few more apps at the same time - I did pretty much anything I
>>>>>> could think of to max out the loading.
>>>>>>
>>>>>> Maximum recorded power demand 159W.
>>>>>>
>>>>>> The difference between the recommended calculated load and the
>>>>>> measured
>>>>>> load is so vast that I'm beginning to doubt myself.
>>>>>
>>>>> Even a fairly powerful PC is unlikely to draw more than 250W
>>>>> continuously. Probably less than 100W most of the time. The other
>>>>> things
>>>>> not much - unlikely to be more than 100W all together. (note that
>>>>> inrush
>>>>> can be much higher - so turning kit on while running on battery can
>>>>> glitch the output enough to drop a load or reboot a PC)
>>>>>
>>>>> So a 650VA UPS would likely be plenty, and leave some capacity to
>>>>> spare.
>>>>> That kind of device is also fairly cheap.
>>>>>
>>>>> Having said that you often find that as the VA rating goes up, at some
>>>>> point so does the battery capacity. So if you only have 500VA max
>>>>> load,
>>>>> it can still be worth going from the (adequate) 600VA to the
>>>>> (overkill)
>>>>> 1kVA to get the bigger batteries and double the run time.
>>>>>
>>>>> (I recently wanted one to hold up a micro form factor PC (fairly high
>>>>> end i7 box - running accounting software in 4 VMs), a synology NAS,
>>>>> and
>>>>> various bits of network kit including a 24 port PoE switch).
>>>>>
>>>>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
>>>>> been plenty. However at half load the unit was only rated for about 6
>>>>> mins. So going for the 1.2kVA version which has twice the battery size
>>>>> gave plenty of time for the orderly shutdown of the NAS and all the
>>>>> VMs
>>>>> if required. (in reality, according to actual load shown on the the
>>>>> power meter on the UPS, it will likely get 60+ mins of runtime)
>>>>>
>>>>> Something else to consider when supporting multiple bits of kit is how
>>>>> you will synch the shutdown of the attached loads. Most UPS devices
>>>>> have
>>>>> a USB connection these days that lets you connect a single PC or other
>>>>> device and monitor it. That also allows you to specify a charge
>>>>> remaining threshold when the device should power down. That is easy
>>>>> with
>>>>> just one PC.
>>>>>
>>>>> However it gets a bit more complicated with multiple devices. There is
>>>>> an open source suite of software called NUT (Network UPS Tools), that
>>>>> allows one device physically talking to the UPS to act as a server and
>>>>> share information about the current power state with multiple
>>>>> clients. I
>>>>> found the Synology box actually uses this for its default UPS
>>>>> monitoring
>>>>> capability (although it does not seem to name it directly). That
>>>>> made it
>>>>> easy to get a NUT client for the main windows machine running the
>>>>> hypervisor, setup the NAS as the NUT server, and point the windows box
>>>>> at that. That the whole lot can be gracefully shutdown in sequence,
>>>>> and
>>>>> then finally switch off the UPS itself as well once the available
>>>>> capacity falls below the desired capacity threshold.
>>>>>
>>>>> (on restoration of mains, everything is configured to come back up can
>>>>> carry on were it left off)
>>>>>
>>>>>> I'm certainly not the first person to go down this route so...
>>>>>> Comments please.
>>>>>
>>>>> I have an extension lead made up with exposed individual wires, so
>>>>> that
>>>>> I can loop them through a clamp meter:
>>>>>
>>>>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_
>>>> (Medium).jpg
>>>>>
>>>>> Makes a handy way to get a feel for the actual size of UPS required.
>>>>
>>>> Amazingly, I have never required a UPS over thirty years of computing.
>>>
>>> If you run a home server, you don't want to risk corruption of the
>>> storage array due to power cuts, brownouts or spikes, so a UPS is a
>>> very good idea. Also useful to avoid having to restart the server if
>>> you need to knock the power off for a few minutes during DIY.
>>>
>>> As we are switched over to digital telephony, a UPS to keep the phone
>>> working may become a good idea too.
>>>
>>
>> You do NOT want to mess up RAID arrays, by doing dirty shutdowns.
>> Yes, there are kinds of equipment you definitely want a UPS.
>>
> I dont run RAID for that reason.
>
> I just have mirror disks, synched once a night.
>
> RAID is not for backup, it is for high availability.
> No domestic setup needs RAID.

True RAID is not a backup strategy, but it is a layer of fault tolerance
that can save downtime. You can also get increased throughput with the
higher level RAID categories as well.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 21/02/2024 11:49, SteveW wrote:
> On 21/02/2024 08:25, Jeff Gaines wrote:
>> On 20/02/2024 in message <Tc8BN.307810$Ama9.225504@fx12.iad> Sam
>> Plusnet wrote:
>>
>>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>>> associated voltage spikes etc.), so I decided to get a UPS to protect
>>> things.
>>
>> When you've finished your calculations this is the modern version of
>> the one I have:
>>
>> https://www.amazon.co.uk/APC-BACK-UPS-BE850G2-UK-Uninterruptible-Protected/dp/B0828G42KN/ref=sr_1_3?dib=eyJ2IjoiMSJ9.br4fFzBVpJA6Vt3vmBchQXARCrvm5q9E075DBvrtPbprDjYIxwhc0kOHf2NhTLAYrEKzSwQXOx690gQqrrVkUhc8W5It17O_kYNRibR-tyBMvWieZT_rgtS9VPI4Co4FmnFcaWSYSq95w4PPudLJ3PZO1Oz9Q3IKEQ6ORpdtvVh3cvGxFE6WPQcOGZpbestpbtrElwJrxJsv0JPzSTnJOlA12NhdfUXULPd1wdMomiM.WGESu0PS-H27OzadV8u7PF_7TO8QkE6jLxFGI3iLHog&dib_tag=se&keywords=apc+backup+ups&sr=8-3&ufe=app_do%3Aamzn1.fos.d7e5a2de-8759-4da3-993c-d11b6e3d217f
>>
>> I've always lived in rural areas with overhead cables so power cuts
>> are frequent. I have it set up so as soon as mains power is lost the
>> PC shuts down, I don't expect it to run the PC in the event of a power
>> cut.
>
> Do you actually have it set to shut the PC down immediately or with a
> couple of minutes' delay? The latter would allow for times when the
> power cuts out, but reconnects shortly after.

I have mine set to initiate shutdown when the reserve power reaches a
threshold (like 20% remaining). That still leaves some scope to power
something back up again during a power cut if it became necessary.

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 21-Feb-24 3:26, John Rumm wrote:
> On 20/02/2024 20:46, Sam Plusnet wrote:
>
>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>> associated voltage spikes etc.), so I decided to get a UPS to protect
>> things.
>>
>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>
>> The next question is "How big a UPS do I need?"
>>
>> I went looking for advice on this, and found most said:
>>
>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating (90W)
>> and the Monitor (78W) to get the max load (1018W) then multiply by 50%
>> (some say 100%) to give some headroom.
>> Some even pointed out that (e.g.) the PC PSU rating was its DC output,
>> so its AC input would be even greater so...
>
> That all sounds a bit excessive...
>
> What graphics card is in the PC?
>
>> Things seemed to be getting completely out of hand, so I decided to
>> measure, not calculate.
>>
>> I put those three items (PC, Monitor & NAS) on a separate supply
>> circuit monitored by a power meter set to record max power draw in
>> watts (VA would have been better, but that's what I had available).
>>
>> Ran things up.  Pulled video down from the NAS & ran it on the PC.
>> Ran up a few more apps at the same time - I did pretty much anything I
>> could think of to max out the loading.
>>
>> Maximum recorded power demand 159W.
>>
>> The difference between the recommended calculated load and the
>> measured load is so vast that I'm beginning to doubt myself.
>
> Even a fairly powerful PC is unlikely to draw more than 250W
> continuously. Probably less than 100W most of the time. The other things
> not much - unlikely to be more than 100W all together. (note that inrush
> can be much higher - so turning kit on while running on battery can
> glitch the output enough to drop a load or reboot a PC)
>
> So a 650VA UPS would likely be plenty, and leave some capacity to spare.
> That kind of device is also fairly cheap.
>
> Having said that you often find that as the VA rating goes up, at some
> point so does the battery capacity. So if you only have 500VA max load,
> it can still be worth going from the (adequate) 600VA to the (overkill)
> 1kVA to get the bigger batteries and double the run time.
>
> (I recently wanted one to hold up a micro form factor PC (fairly high
> end i7 box - running accounting software in 4 VMs), a synology NAS, and
> various bits of network kit including a 24 port PoE switch).
>
> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
> been plenty. However at half load the unit was only rated for about 6
> mins. So going for the 1.2kVA version which has twice the battery size
> gave plenty of time for the orderly shutdown of the NAS and all the VMs
> if required. (in reality, according to actual load shown on the the
> power meter on the UPS, it will likely get 60+ mins of runtime)

Exactly the model (1200VA) I am contemplating - but when I placed an
order for one, the supplier insisted that Cyberpower required a signed
statement that it was to be supplied as a commercial item, and limiting
some of a retail customer's rights. They also claimed that this didn't
reduce my statutory rights - but I didn't accept that.
>
> Something else to consider when supporting multiple bits of kit is how
> you will synch the shutdown of the attached loads. Most UPS devices have
> a USB connection these days that lets you connect a single PC or other
> device and monitor it. That also allows you to specify a charge
> remaining threshold when the device should power down. That is easy with
> just one PC.

I intend to use the USB connection to do a controlled shutdown of the
NAS - that being the most vulnerable item. If the PC is running, I
should be sat in front of it, or close enough, and so able to do a
manual shutdown in plenty of time.
>
> However it gets a bit more complicated with multiple devices. There is
> an open source suite of software called NUT (Network UPS Tools), that
> allows one device physically talking to the UPS to act as a server and
> share information about the current power state with multiple clients. I
> found the Synology box actually uses this for its default UPS monitoring
> capability (although it does not seem to name it directly). That made it
> easy to get a NUT client for the main windows machine running the
> hypervisor, setup the NAS as the NUT server, and point the windows box
> at that. That the whole lot can be gracefully shutdown in sequence, and
> then finally switch off the UPS itself as well once the available
> capacity falls below the desired capacity threshold.
>
> (on restoration of mains, everything is configured to come back up can
> carry on were it left off)
>
>> I'm certainly not the first person to go down this route so...
>> Comments please.
>
> I have an extension lead made up with exposed individual wires, so that
> I can loop them through a clamp meter:
>
> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_(Medium).jpg
>
> Makes a handy way to get a feel for the actual size of UPS required.
>

--
Sam Plusnet

On 21-Feb-24 15:29, NY wrote:
> On 21/02/2024 03:26, John Rumm wrote:
>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>> I put those three items (PC, Monitor & NAS) on a separate supply
>>> circuit monitored by a power meter set to record max power draw in
>>> watts (VA would have been better, but that's what I had available).
>>>
>>> Ran things up.  Pulled video down from the NAS & ran it on the PC.
>>> Ran up a few more apps at the same time - I did pretty much anything
>>> I could think of to max out the loading.
>>>
>>> Maximum recorded power demand 159W.
>>>
>>> The difference between the recommended calculated load and the
>>> measured load is so vast that I'm beginning to doubt myself.
>>
>> Even a fairly powerful PC is unlikely to draw more than 250W
>> continuously. Probably less than 100W most of the time. The other
>> things not much - unlikely to be more than 100W all together. (note
>> that inrush can be much higher - so turning kit on while running on
>> battery can glitch the output enough to drop a load or reboot a PC)
>>
>> So a 650VA UPS would likely be plenty, and leave some capacity to
>> spare. That kind of device is also fairly cheap.
>>
>> Having said that you often find that as the VA rating goes up, at some
>> point so does the battery capacity. So if you only have 500VA max
>> load, it can still be worth going from the (adequate) 600VA to the
>> (overkill) 1kVA to get the bigger batteries and double the run time.
>>
>> (I recently wanted one to hold up a micro form factor PC (fairly high
>> end i7 box - running accounting software in 4 VMs), a synology NAS,
>> and various bits of network kit including a 24 port PoE switch).
>>
>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
>> been plenty. However at half load the unit was only rated for about 6
>> mins. So going for the 1.2kVA version which has twice the battery size
>> gave plenty of time for the orderly shutdown of the NAS and all the
>> VMs if required. (in reality, according to actual load shown on the
>> the power meter on the UPS, it will likely get 60+ mins of runtime)
>>
>> Something else to consider when supporting multiple bits of kit is how
>> you will synch the shutdown of the attached loads. Most UPS devices
>> have a USB connection these days that lets you connect a single PC or
>> other device and monitor it. That also allows you to specify a charge
>> remaining threshold when the device should power down. That is easy
>> with just one PC.
>>
>> However it gets a bit more complicated with multiple devices. There is
>> an open source suite of software called NUT (Network UPS Tools), that
>> allows one device physically talking to the UPS to act as a server and
>> share information about the current power state with multiple clients.
>> I found the Synology box actually uses this for its default UPS
>> monitoring capability (although it does not seem to name it directly).
>> That made it easy to get a NUT client for the main windows machine
>> running the hypervisor, setup the NAS as the NUT server, and point the
>> windows box at that. That the whole lot can be gracefully shutdown in
>> sequence, and then finally switch off the UPS itself as well once the
>> available capacity falls below the desired capacity threshold.
>>
>> (on restoration of mains, everything is configured to come back up can
>> carry on were it left off)
>>
>>> I'm certainly not the first person to go down this route so...
>>> Comments please.
>>
>> I have an extension lead made up with exposed individual wires, so
>> that I can loop them through a clamp meter:
>>
>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_(Medium).jpg
>>
>> Makes a handy way to get a feel for the actual size of UPS required.
>
> The one piece of advice that I would give you, from learning the hard
> way, is when you receive the UPS, bite the bullet and actually make sure
> it works while it's still in warranty, and do it at a time when you can
> manage without the various computers, both when you are shutting them
> down cleanly to allow the UPS to be interposed between the mains and the
> computers, and when you simulate a loss of mains and hope that the UPS
> will work.
>
> My wife bought an expensive PC which came with a UPS - probably rated at
> 700 VA since that was a common size at the time.
>
> We didn't test it at the time, and only got round to trying it a year or
> so later, by which time its manufacturer's warranty had expired. Add it
> was as dead as a dodo. Even after leaving the battery on charge for a
> couple of days (vastly excess of what its battery should need), it would
> not supply any power.
>
> I took it out of the PC setup and tried it in isolation. It lit a 60 W
> tungsten bulb for about 5 seconds. It lit a 7 W LED bulb (Philips Hue,
> IIRC) for about 15 seconds. Powered by the mains, and connected to a PC
> by mains and by its USB monitoring connection, with the PC running the
> UPS's monitoring software, the UPS reported the battery state as
> "excellent" but the UPS would not run off that battery.
>
> This is something I have experienced in several situations. I have a
> Samsung laptop and its battery is reported by Windows and by MX Linux
> (booting off different HDDs) as 100% capacity while connected to the
> mains PSU/charger, but as soon as I unplug the PSU, the laptop turns off
> instantaneously.
>
> It seems that laptops and UPSes can "see" their battery as holding a
> full charge, but as soon as you remove the power input, the device stops
> working, as if the battery is really as flat as a pancake.
>
> IN my experience, don't trust the UPS hardware and software to tell the
> truth - test it periodically by simulating a power cut.
>
> And simulate the type of power cut that you typically get. It may be a
> long power cut or it may be a series of brief 1-second cuts in rapid
> succession. My Windows 7 PC seems to be fine with a single power cut
> (whether brief or several hours) and will always boot fine afterwards.
> But several 1-second cuts at 10-second intervals will knacker the HDD.
> Not irreparably, but enough to require a very long file-system check
> before it will start to boot.

Thanks. That sounds like very good advice.

I've read reports of people who said their UPS claimed to be at 100%,
but then fell over in a few seconds with only a minor imposed load.
However I hadn't thought of the warranty aspect.

--
Sam Plusnet

On 21-Feb-24 12:03, Paul wrote:
> On 2/20/2024 3:46 PM, Sam Plusnet wrote:
>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the associated voltage spikes etc.), so I decided to get a UPS to protect things.
>>
>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>
>> The next question is "How big a UPS do I need?"
>>
>> I went looking for advice on this, and found most said:
>>
>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating (90W) and the Monitor (78W) to get the max load (1018W) then multiply by 50% (some say 100%) to give some headroom.
>> Some even pointed out that (e.g.) the PC PSU rating was its DC output, so its AC input would be even greater so...
>>
>> Things seemed to be getting completely out of hand, so I decided to measure, not calculate.
>>
>> I put those three items (PC, Monitor & NAS) on a separate supply circuit monitored by a power meter set to record max power draw in watts (VA would have been better, but that's what I had available).
>>
>> Ran things up.  Pulled video down from the NAS & ran it on the PC.  Ran up a few more apps at the same time - I did pretty much anything I could think of to max out the loading.
>>
>> Maximum recorded power demand 159W.
>>
>> The difference between the recommended calculated load and the measured load is so vast that I'm beginning to doubt myself.
>>
>> I'm certainly not the first person to go down this route so...  Comments please.
>>
>
> For a PC, I use a copy of Furmark to max out the GPU. And
> a copy of Prime95 or use 7ZIP compression, to keep the CPU busy.
>
> On this machine, that would be 300W. Without the goading,
> a "typical busy value" would be 136W, which is railing on
> one CPU core, without the GPU in usage. That's the difference
> a "power test setup" makes to the demand result.
>
> On the other machine, it will draw 400W, 180W for the graphics card.
> Most of the time, it runs 100W-180W if not goaded.
>
> But the power meter is the right approach. Measurement as a
> means to reflect some degree of reality. The NAS and the display device,
> they might have more static loads for all I know.

Indeed.
Choices made should reflect the expected use-case. I rarely play games
now, and the ones that I do are not going to stress a modern system too
much.
If a power cut (greater than a second or two) happens, I want the UPS to
hold up long enough for me to save files and safely power down all
systems - not to carry on playing some cutting-edge game at max settings
for the next hour or two.
>
> I originally budgeted for one PC on the UPS, but eventually
> had two on it. You would not expect too many cases where
> they would go-to-max on their own. The UPS is disconnected
> at the moment, because the battery is dead, and I did not
> like the failure mode it displayed.

That's another good point. You buy a UPS to support the setup you have
- but we all tend to change kit from time to time. It usually pays to
be generous when specifying.

--
Sam Plusnet

On 21 Feb 2024 at 15:29:40 GMT, "NY" <me@privacy.net> wrote:

> IN my experience, don't trust the UPS hardware and software to tell the
> truth - test it periodically by simulating a power cut.

Good advice, but we don't have to simulate them here.

--
"Freedom is sloppy. But since tyranny's the only guaranteed byproduct of those who insist on a perfect world, freedom will have to do." -- Bigby Wolf

On 21/02/2024 20:10, John Rumm wrote:
> On 21/02/2024 14:12, The Natural Philosopher wrote:
>> On 21/02/2024 13:01, Paul wrote:
>>> On 2/21/2024 6:47 AM, SteveW wrote:
>>>> On 21/02/2024 05:48, Sid@home.com wrote:
>>>>> On Wed, 21 Feb 2024 03:26:37 +0000, John Rumm wrote:
>>>>>
>>>>>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>>>>>
>>>>>>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>>>>>>> associated voltage spikes etc.), so I decided to get a UPS to
>>>>>>> protect
>>>>>>> things.
>>>>>>>
>>>>>>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>>>>>>
>>>>>>> The next question is "How big a UPS do I need?"
>>>>>>>
>>>>>>> I went looking for advice on this, and found most said:
>>>>>>>
>>>>>>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating
>>>>>>> (90W)
>>>>>>> and the Monitor (78W) to get the max load (1018W) then multiply
>>>>>>> by 50%
>>>>>>> (some say 100%) to give some headroom.
>>>>>>> Some even pointed out that (e.g.) the PC PSU rating was its DC
>>>>>>> output,
>>>>>>> so its AC input would be even greater so...
>>>>>>
>>>>>> That all sounds a bit excessive...
>>>>>>
>>>>>> What graphics card is in the PC?
>>>>>>
>>>>>>> Things seemed to be getting completely out of hand, so I decided to
>>>>>>> measure, not calculate.
>>>>>>>
>>>>>>> I put those three items (PC, Monitor & NAS) on a separate supply
>>>>>>> circuit monitored by a power meter set to record max power draw in
>>>>>>> watts (VA would have been better, but that's what I had available).
>>>>>>>
>>>>>>> Ran things up.  Pulled video down from the NAS & ran it on the
>>>>>>> PC.  Ran
>>>>>>> up a few more apps at the same time - I did pretty much anything I
>>>>>>> could think of to max out the loading.
>>>>>>>
>>>>>>> Maximum recorded power demand 159W.
>>>>>>>
>>>>>>> The difference between the recommended calculated load and the
>>>>>>> measured
>>>>>>> load is so vast that I'm beginning to doubt myself.
>>>>>>
>>>>>> Even a fairly powerful PC is unlikely to draw more than 250W
>>>>>> continuously. Probably less than 100W most of the time. The other
>>>>>> things
>>>>>> not much - unlikely to be more than 100W all together. (note that
>>>>>> inrush
>>>>>> can be much higher - so turning kit on while running on battery can
>>>>>> glitch the output enough to drop a load or reboot a PC)
>>>>>>
>>>>>> So a 650VA UPS would likely be plenty, and leave some capacity to
>>>>>> spare.
>>>>>> That kind of device is also fairly cheap.
>>>>>>
>>>>>> Having said that you often find that as the VA rating goes up, at
>>>>>> some
>>>>>> point so does the battery capacity. So if you only have 500VA max
>>>>>> load,
>>>>>> it can still be worth going from the (adequate) 600VA to the
>>>>>> (overkill)
>>>>>> 1kVA to get the bigger batteries and double the run time.
>>>>>>
>>>>>> (I recently wanted one to hold up a micro form factor PC (fairly high
>>>>>> end i7 box - running accounting software in 4 VMs), a synology
>>>>>> NAS, and
>>>>>> various bits of network kit including a 24 port PoE switch).
>>>>>>
>>>>>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would
>>>>>> have
>>>>>> been plenty. However at half load the unit was only rated for about 6
>>>>>> mins. So going for the 1.2kVA version which has twice the battery
>>>>>> size
>>>>>> gave plenty of time for the orderly shutdown of the NAS and all
>>>>>> the VMs
>>>>>> if required. (in reality, according to actual load shown on the the
>>>>>> power meter on the UPS, it will likely get 60+ mins of runtime)
>>>>>>
>>>>>> Something else to consider when supporting multiple bits of kit is
>>>>>> how
>>>>>> you will synch the shutdown of the attached loads. Most UPS
>>>>>> devices have
>>>>>> a USB connection these days that lets you connect a single PC or
>>>>>> other
>>>>>> device and monitor it. That also allows you to specify a charge
>>>>>> remaining threshold when the device should power down. That is
>>>>>> easy with
>>>>>> just one PC.
>>>>>>
>>>>>> However it gets a bit more complicated with multiple devices.
>>>>>> There is
>>>>>> an open source suite of software called NUT (Network UPS Tools), that
>>>>>> allows one device physically talking to the UPS to act as a server
>>>>>> and
>>>>>> share information about the current power state with multiple
>>>>>> clients. I
>>>>>> found the Synology box actually uses this for its default UPS
>>>>>> monitoring
>>>>>> capability (although it does not seem to name it directly). That
>>>>>> made it
>>>>>> easy to get a NUT client for the main windows machine running the
>>>>>> hypervisor, setup the NAS as the NUT server, and point the windows
>>>>>> box
>>>>>> at that. That the whole lot can be gracefully shutdown in
>>>>>> sequence, and
>>>>>> then finally switch off the UPS itself as well once the available
>>>>>> capacity falls below the desired capacity threshold.
>>>>>>
>>>>>> (on restoration of mains, everything is configured to come back up
>>>>>> can
>>>>>> carry on were it left off)
>>>>>>
>>>>>>> I'm certainly not the first person to go down this route so...
>>>>>>> Comments please.
>>>>>>
>>>>>> I have an extension lead made up with exposed individual wires, so
>>>>>> that
>>>>>> I can loop them through a clamp meter:
>>>>>>
>>>>>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_
>>>>> (Medium).jpg
>>>>>>
>>>>>> Makes a handy way to get a feel for the actual size of UPS required.
>>>>>
>>>>> Amazingly, I have never required a UPS over thirty years of computing.
>>>>
>>>> If you run a home server, you don't want to risk corruption of the
>>>> storage array due to power cuts, brownouts or spikes, so a UPS is a
>>>> very good idea. Also useful to avoid having to restart the server if
>>>> you need to knock the power off for a few minutes during DIY.
>>>>
>>>> As we are switched over to digital telephony, a UPS to keep the
>>>> phone working may become a good idea too.
>>>>
>>>
>>> You do NOT want to mess up RAID arrays, by doing dirty shutdowns.
>>> Yes, there are kinds of equipment you definitely want a UPS.
>>>
>> I dont run RAID for that reason.
>>
>> I just have mirror disks, synched once a night.
>>
>> RAID is not for backup, it is for high availability.
>> No domestic setup needs RAID.
>
> True RAID is not a backup strategy, but it is a layer of fault tolerance
> that can save downtime. You can also get increased throughput with the
> higher level RAID categories as well.

Yes. My RAID has a battery backed buffer and is very tolerant of sudden
shutdown and of course of a disk failure, it also does increase
throughput and allows a greater total capacity than mirroring. Of course
I do back up to another place.

On 2/21/2024 9:12 AM, The Natural Philosopher wrote:
> On 21/02/2024 13:01, Paul wrote:
>> On 2/21/2024 6:47 AM, SteveW wrote:
>>> On 21/02/2024 05:48, Sid@home.com wrote:
>>>> On Wed, 21 Feb 2024 03:26:37 +0000, John Rumm wrote:
>>>>
>>>>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>>>>
>>>>>> I lost a PC PSU to a couple of micro-power cuts and (no doubt the
>>>>>> associated voltage spikes etc.), so I decided to get a UPS to protect
>>>>>> things.
>>>>>>
>>>>>> I only want to support the desktop PC, Monitor and my 4 bay NAS.
>>>>>>
>>>>>> The next question is "How big a UPS do I need?"
>>>>>>
>>>>>> I went looking for advice on this, and found most said:
>>>>>>
>>>>>> "Add the PC PSU rating (850W in this case) to the NAS PSU rating (90W)
>>>>>> and the Monitor (78W) to get the max load (1018W) then multiply by 50%
>>>>>> (some say 100%) to give some headroom.
>>>>>> Some even pointed out that (e.g.) the PC PSU rating was its DC output,
>>>>>> so its AC input would be even greater so...
>>>>>
>>>>> That all sounds a bit excessive...
>>>>>
>>>>> What graphics card is in the PC?
>>>>>
>>>>>> Things seemed to be getting completely out of hand, so I decided to
>>>>>> measure, not calculate.
>>>>>>
>>>>>> I put those three items (PC, Monitor & NAS) on a separate supply
>>>>>> circuit monitored by a power meter set to record max power draw in
>>>>>> watts (VA would have been better, but that's what I had available).
>>>>>>
>>>>>> Ran things up.  Pulled video down from the NAS & ran it on the PC.  Ran
>>>>>> up a few more apps at the same time - I did pretty much anything I
>>>>>> could think of to max out the loading.
>>>>>>
>>>>>> Maximum recorded power demand 159W.
>>>>>>
>>>>>> The difference between the recommended calculated load and the measured
>>>>>> load is so vast that I'm beginning to doubt myself.
>>>>>
>>>>> Even a fairly powerful PC is unlikely to draw more than 250W
>>>>> continuously. Probably less than 100W most of the time. The other things
>>>>> not much - unlikely to be more than 100W all together. (note that inrush
>>>>> can be much higher - so turning kit on while running on battery can
>>>>> glitch the output enough to drop a load or reboot a PC)
>>>>>
>>>>> So a 650VA UPS would likely be plenty, and leave some capacity to spare.
>>>>> That kind of device is also fairly cheap.
>>>>>
>>>>> Having said that you often find that as the VA rating goes up, at some
>>>>> point so does the battery capacity. So if you only have 500VA max load,
>>>>> it can still be worth going from the (adequate) 600VA to the (overkill)
>>>>> 1kVA to get the bigger batteries and double the run time.
>>>>>
>>>>> (I recently wanted one to hold up a micro form factor PC (fairly high
>>>>> end i7 box - running accounting software in 4 VMs), a synology NAS, and
>>>>> various bits of network kit including a 24 port PoE switch).
>>>>>
>>>>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
>>>>> been plenty. However at half load the unit was only rated for about 6
>>>>> mins. So going for the 1.2kVA version which has twice the battery size
>>>>> gave plenty of time for the orderly shutdown of the NAS and all the VMs
>>>>> if required. (in reality, according to actual load shown on the the
>>>>> power meter on the UPS, it will likely get 60+ mins of runtime)
>>>>>
>>>>> Something else to consider when supporting multiple bits of kit is how
>>>>> you will synch the shutdown of the attached loads. Most UPS devices have
>>>>> a USB connection these days that lets you connect a single PC or other
>>>>> device and monitor it. That also allows you to specify a charge
>>>>> remaining threshold when the device should power down. That is easy with
>>>>> just one PC.
>>>>>
>>>>> However it gets a bit more complicated with multiple devices. There is
>>>>> an open source suite of software called NUT (Network UPS Tools), that
>>>>> allows one device physically talking to the UPS to act as a server and
>>>>> share information about the current power state with multiple clients. I
>>>>> found the Synology box actually uses this for its default UPS monitoring
>>>>> capability (although it does not seem to name it directly). That made it
>>>>> easy to get a NUT client for the main windows machine running the
>>>>> hypervisor, setup the NAS as the NUT server, and point the windows box
>>>>> at that. That the whole lot can be gracefully shutdown in sequence, and
>>>>> then finally switch off the UPS itself as well once the available
>>>>> capacity falls below the desired capacity threshold.
>>>>>
>>>>> (on restoration of mains, everything is configured to come back up can
>>>>> carry on were it left off)
>>>>>
>>>>>> I'm certainly not the first person to go down this route so...
>>>>>> Comments please.
>>>>>
>>>>> I have an extension lead made up with exposed individual wires, so that
>>>>> I can loop them through a clamp meter:
>>>>>
>>>>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_
>>>> (Medium).jpg
>>>>>
>>>>> Makes a handy way to get a feel for the actual size of UPS required.
>>>>
>>>> Amazingly, I have never required a UPS over thirty years of computing.
>>>
>>> If you run a home server, you don't want to risk corruption of the storage array due to power cuts, brownouts or spikes, so a UPS is a very good idea. Also useful to avoid having to restart the server if you need to knock the power off for a few minutes during DIY.
>>>
>>> As we are switched over to digital telephony, a UPS to keep the phone working may become a good idea too.
>>>
>>
>> You do NOT want to mess up RAID arrays, by doing dirty shutdowns.
>> Yes, there are kinds of equipment you definitely want a UPS.
>>
> I dont run RAID for that reason.
>
> I just have mirror disks, synched once a night.
>
> RAID is not for backup, it is for high availability.
> No domestic setup needs RAID.
>
>
> ...
>
>>
>> RAID arrays still need backups. And a UPS helps prevent them
>> from becoming de-synchronized.
>>
> So whats  the point of RAID?
> In short its not a data protection strategy at all, its high availability to data in a data centre
>
>> I do not really know what keeps consumer SSDs alive on power failures.
>
> They are not kept alive.
> They shut down smoothly. Probably have big capacitors to flush writes to the NVRAM if they detect power failure. I pull the plug on mine often, without issue.
>
>
>> It's supposed to be a "firmware scheme", but since they don't have
>> advanced power fail detection (and a Supercap), it's not hardware
>> that protects them against critical data loss. It's hard to imagine the
>> flash has sufficient life for any sort of firmware scheme to make
>> the device "reliable".
>
> You appear to be babbling.
>
> Flash doesn't need power to retain data, It will only cache data in RAM for a short while before writing it, and the time to write it if external power goes down is microseconds. It doesn't need a supercap. An ordinary one will do. And it doesn't need 'advanced power fail detection' a simple monitor of supply voltage on the far side of a diode will serve to tell them they have lost external power and to flush all caches to NVRAM now.
>
> How do you *think* SSDS would work if you shutdown the computer they are attached to?  They don't have a 'shutdown' signal. They just get the power removed. They presumably simply DO monitor supply voltages .
>

On 2/21/2024 10:29 AM, NY wrote:
> On 21/02/2024 03:26, John Rumm wrote:
>> On 20/02/2024 20:46, Sam Plusnet wrote:
>>> I put those three items (PC, Monitor & NAS) on a separate supply circuit monitored by a power meter set to record max power draw in watts (VA would have been better, but that's what I had available).
>>>
>>> Ran things up.  Pulled video down from the NAS & ran it on the PC.  Ran up a few more apps at the same time - I did pretty much anything I could think of to max out the loading.
>>>
>>> Maximum recorded power demand 159W.
>>>
>>> The difference between the recommended calculated load and the measured load is so vast that I'm beginning to doubt myself.
>>
>> Even a fairly powerful PC is unlikely to draw more than 250W continuously. Probably less than 100W most of the time. The other things not much - unlikely to be more than 100W all together. (note that inrush can be much higher - so turning kit on while running on battery can glitch the output enough to drop a load or reboot a PC)
>>
>> So a 650VA UPS would likely be plenty, and leave some capacity to spare. That kind of device is also fairly cheap.
>>
>> Having said that you often find that as the VA rating goes up, at some point so does the battery capacity. So if you only have 500VA max load, it can still be worth going from the (adequate) 600VA to the (overkill) 1kVA to get the bigger batteries and double the run time.
>>
>> (I recently wanted one to hold up a micro form factor PC (fairly high end i7 box - running accounting software in 4 VMs), a synology NAS, and various bits of network kit including a 24 port PoE switch).
>>
>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have been plenty. However at half load the unit was only rated for about 6 mins. So going for the 1.2kVA version which has twice the battery size gave plenty of time for the orderly shutdown of the NAS and all the VMs if required. (in reality, according to actual load shown on the the power meter on the UPS, it will likely get 60+ mins of runtime)
>>
>> Something else to consider when supporting multiple bits of kit is how you will synch the shutdown of the attached loads. Most UPS devices have a USB connection these days that lets you connect a single PC or other device and monitor it. That also allows you to specify a charge remaining threshold when the device should power down. That is easy with just one PC.
>>
>> However it gets a bit more complicated with multiple devices. There is an open source suite of software called NUT (Network UPS Tools), that allows one device physically talking to the UPS to act as a server and share information about the current power state with multiple clients. I found the Synology box actually uses this for its default UPS monitoring capability (although it does not seem to name it directly). That made it easy to get a NUT client for the main windows machine running the hypervisor, setup the NAS as the NUT server, and point the windows box at that. That the whole lot can be gracefully shutdown in sequence, and then finally switch off the UPS itself as well once the available capacity falls below the desired capacity threshold.
>>
>> (on restoration of mains, everything is configured to come back up can carry on were it left off)
>>
>>> I'm certainly not the first person to go down this route so...  Comments please.
>>
>> I have an extension lead made up with exposed individual wires, so that I can loop them through a clamp meter:
>>
>> https://wiki.diyfaq.org.uk/index.php/File:MainsCurrentTestLead_(Medium).jpg
>>
>> Makes a handy way to get a feel for the actual size of UPS required.
>
> The one piece of advice that I would give you, from learning the hard way, is when you receive the UPS, bite the bullet and actually make sure it works while it's still in warranty, and do it at a time when you can manage without the various computers, both when you are shutting them down cleanly to allow the UPS to be interposed between the mains and the computers, and when you simulate a loss of mains and hope that the UPS will work.
>
> My wife bought an expensive PC which came with a UPS - probably rated at 700 VA since that was a common size at the time.
>
> We didn't test it at the time, and only got round to trying it a year or so later, by which time its manufacturer's warranty had expired. Add it was as dead as a dodo. Even after leaving the battery on charge for a couple of days (vastly excess of what its battery should need), it would not supply any power.
>
> I took it out of the PC setup and tried it in isolation. It lit a 60 W tungsten bulb for about 5 seconds. It lit a 7 W LED bulb (Philips Hue, IIRC) for about 15 seconds. Powered by the mains, and connected to a PC by mains and by its USB monitoring connection, with the PC running the UPS's monitoring software, the UPS reported the battery state as "excellent" but the UPS would not run off that battery.
>
> This is something I have experienced in several situations. I have a Samsung laptop and its battery is reported by Windows and by MX Linux (booting off different HDDs) as 100% capacity while connected to the mains PSU/charger, but as soon as I unplug the PSU, the laptop turns off instantaneously.
>
> It seems that laptops and UPSes can "see" their battery as holding a full charge, but as soon as you remove the power input, the device stops working, as if the battery is really as flat as a pancake.
>
> IN my experience, don't trust the UPS hardware and software to tell the truth - test it periodically by simulating a power cut.
>
> And simulate the type of power cut that you typically get. It may be a long power cut or it may be a series of brief 1-second cuts in rapid succession. My Windows 7 PC seems to be fine with a single power cut (whether brief or several hours) and will always boot fine afterwards. But several 1-second cuts at 10-second intervals will knacker the HDD. Not irreparably, but enough to require a very long file-system check before it will start to boot.

They do a battery test, once a day. A kind of impedance test.

If the battery fails the load test, the unit will beep once.

There may also be a button on the casing, that does a
"flip to battery" inverter test. It simulates loss of
mains. But even without inverter testing, it will check
the battery for you.

Modern UPS can have a tiny display on them and a CPU,
and so there is a better chance the response will be
intelligible. On my old one, it's all meant to be
mysterious.

On an SPS UPS (the lowest form), the chassis is made
of a piece of heavy steel. And it is ice cold to the
touch. If you feel the chassis, and the chassis is
a bit warm to the touch, this means cells in the lead acid
battery have failed short, and the battery has changed from
a 12V battery, to a 6V battery with three cells shorted.

By feeling the heat, that's when I knew it was time to take
it out of service.

High end ones, double conversion with sine wave output in
server rooms, those have a fan, and the inverter is running
all the time. Those are more likely to be well designed.
And do a more thorough job on test.

At work we bought more than 100 UPS in a bulk purchase,
and put them on the office computers. These were cheap SPS
(Standby Power Supply) type UPS. The failure rate off
the pallet was 10%. Some units would not flip to battery
on loss of mains. Some units would not flip off battery
when mains power returned. The nicely distributed flaw
types, suggest the units were not acceptance tested
before being shipped.

Units ship with the battery disconnected from the unit.
This might prevent some amount of self discharge. I
don't really know what the "shelf life" of a boxed UPS
is, in terms of not damaging the battery by leaving it sit.

Battery life, is all over the place. Original battery lasted
11 years (perhaps longer than what other people experience).
The battery still had full voltage (no shorted cells), but
no longer had good capacity. The battery impedance test
once a day, indicated it needed help. But it still behaved
like a 12V battery.

The replacement lasted 3 years, and the chassis got warm on
the replacement battery life cycle. Measurement with a
meter later, indicated that half the cells had failed short
and it was then a 6V battery instead of a 12V one.

Checking the float charge (operating the UPS without the
cover on it), the float was 13.5V, which is more or less
what I expected it to be. If the float wasn't right for
the replacement pack, that could lead to a short life.
But the replacement was branded, so the company should
have checked that the Chinese battery actually had the
right characteristics. Even the *original* 11 year battery
(with branding label adhered over the Chinese name),
was a Chinese one, so it's not that it is Chinese that
mattered. Something must have been wrong with the specs
of the second lot.

And there still aren't a lot of lithium based ones. If done
that way, they should be LFP (lower density, but happy go lucky).
I'm not sure the UPS companies are prepared for the liabilities
involved.

On 22-Feb-24 6:43, Paul wrote:
> Battery life, is all over the place. Original battery lasted
> 11 years (perhaps longer than what other people experience).
> The battery still had full voltage (no shorted cells), but
> no longer had good capacity. The battery impedance test
> once a day, indicated it needed help. But it still behaved
> like a 12V battery.
>
> The replacement lasted 3 years, and the chassis got warm on
> the replacement battery life cycle. Measurement with a
> meter later, indicated that half the cells had failed short
> and it was then a 6V battery instead of a 12V one.

--
Sam Plusnet

On 22-Feb-24 6:43, Paul wrote:

> Battery life, is all over the place. Original battery lasted
> 11 years (perhaps longer than what other people experience).
> The battery still had full voltage (no shorted cells), but
> no longer had good capacity. The battery impedance test
> once a day, indicated it needed help. But it still behaved
> like a 12V battery.
>
> The replacement lasted 3 years, and the chassis got warm on
> the replacement battery life cycle. Measurement with a
> meter later, indicated that half the cells had failed short
> and it was then a 6V battery instead of a 12V one.

I've noticed that the price of replacement batteries from the UPS
manufacturer are terribly expensive.
e.g. a 7AH 12v sealed lead acid Yuasa battery can be had for £15 or so.
An (apparently) identical battery specified for a APC UPS is around £70.

For domestic users, is there a good reason to pay the extra?

--
Sam Plusnet

On Thu, 22 Feb 2024 20:14:52 +0000, Sam Plusnet wrote:

> On 22-Feb-24 6:43, Paul wrote:
>
>> Battery life, is all over the place. Original battery lasted 11 years
>> (perhaps longer than what other people experience).
>> The battery still had full voltage (no shorted cells), but no longer
>> had good capacity. The battery impedance test once a day, indicated it
>> needed help. But it still behaved like a 12V battery.
>>
>> The replacement lasted 3 years, and the chassis got warm on the
>> replacement battery life cycle. Measurement with a meter later,
>> indicated that half the cells had failed short and it was then a 6V
>> battery instead of a 12V one.
>
> I've noticed that the price of replacement batteries from the UPS
> manufacturer are terribly expensive.
> e.g. a 7AH 12v sealed lead acid Yuasa battery can be had for £15 or so.
> An (apparently) identical battery specified for a APC UPS is around £70.
>
> For domestic users, is there a good reason to pay the extra?

I bought one set of APC batteries.

After that I moved to a third party supplier [1] and the life is just as
good. They claim that it's actually the same manufacturer.

[1] In the UK; MDS Battery.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On 2/22/2024 4:20 PM, Bob Eager wrote:
> On Thu, 22 Feb 2024 20:14:52 +0000, Sam Plusnet wrote:
>
>> On 22-Feb-24 6:43, Paul wrote:
>>
>>> Battery life, is all over the place. Original battery lasted 11 years
>>> (perhaps longer than what other people experience).
>>> The battery still had full voltage (no shorted cells), but no longer
>>> had good capacity. The battery impedance test once a day, indicated it
>>> needed help. But it still behaved like a 12V battery.
>>>
>>> The replacement lasted 3 years, and the chassis got warm on the
>>> replacement battery life cycle. Measurement with a meter later,
>>> indicated that half the cells had failed short and it was then a 6V
>>> battery instead of a 12V one.
>>
>> I've noticed that the price of replacement batteries from the UPS
>> manufacturer are terribly expensive.
>> e.g. a 7AH 12v sealed lead acid Yuasa battery can be had for £15 or so.
>> An (apparently) identical battery specified for a APC UPS is around £70.
>>
>> For domestic users, is there a good reason to pay the extra?
>
> I bought one set of APC batteries.
>
> After that I moved to a third party supplier [1] and the life is just as
> good. They claim that it's actually the same manufacturer.
>
> [1] In the UK; MDS Battery.
>
Based on my small sampling here, the replacements
are more or less generic anyway.

Sometimes batteries jam in the tray or cavity in the unit,
and usually there are screws you can access, to release
the thing. I had to buy an extra-long screwdriver, just
so I could get the last duff one, out of the chassis. My
regular screwdrivers weren't long enough.

Paul

On 21/02/2024 20:27, Sam Plusnet wrote:
> On 21-Feb-24 3:26, John Rumm wrote:

>> I was looking at a CyberPower BRICs unit, and the 1kVA/600W would have
>> been plenty. However at half load the unit was only rated for about 6
>> mins. So going for the 1.2kVA version which has twice the battery size
>> gave plenty of time for the orderly shutdown of the NAS and all the
>> VMs if required. (in reality, according to actual load shown on the
>> the power meter on the UPS, it will likely get 60+ mins of runtime)
>
> Exactly the model (1200VA) I am contemplating - but when I placed an
> order for one, the supplier insisted that Cyberpower required a signed
> statement that it was to be supplied as a commercial item, and limiting
> some of a retail customer's rights. They also claimed that this didn't
> reduce my statutory rights - but I didn't accept that.

Sounds a bit odd... they are a standard line with one of my suppliers,
and there are no end user restrictions.

It might be because Cyberpower do provide the warranty cover themselves
- and would rather deal with the customer directly in the case of a
claim rather than through the retailer. (but that is fairly common with
lots of IT kit these days)

https://www.cyberpower.com/uk/en/product/sku/br1200elcd-uk#overview

--
Cheers,

John.

/=================================================================\
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| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

Sam Plusnet wrote:

> The battery impedance test once a day, indicated it needed help. But
> it still behaved like a 12V battery.

With APC (at least the older ones) I came to the conclusion that doing
the regular tests harmed the battery life.

Sam Plusnet wrote:
> I've noticed that the price of replacement batteries from the UPS
> manufacturer are terribly expensive.
> e.g. a 7AH 12v sealed lead acid Yuasa battery can be had for £15 or so.
> An (apparently) identical battery specified for a APC UPS is around £70.
>
> For domestic users, is there a good reason to pay the extra?
I've used Tayna Powerline for quite a few years now, no problem.
<https://www.tayna.co.uk/ups-batteries/powerline/pu7>
if you need more than one, do look out for their lower pricing on pairs
<https://www.tayna.co.uk/ups-batteries/powerline/pu27>

Paul wrote:

> Sometimes batteries jam in the tray or cavity in the unit,
> and usually there are screws you can access, to release
> the thing. I had to buy an extra-long screwdriver, just
> so I could get the last duff one, out of the chassis. My
> regular screwdrivers weren't long enough.

This was the "best" example of that I ever encountered, the battery
wasn't the correct type for cyclic use, the UPS was shoved in a hot cupboard

<http://andyburns.uk/misc/APC_UPS_battery.jpg>

On 22/02/2024 20:14, Sam Plusnet wrote:
> On 22-Feb-24 6:43, Paul wrote:
>
>> Battery life, is all over the place. Original battery lasted
>> 11 years (perhaps longer than what other people experience).
>> The battery still had full voltage (no shorted cells), but
>> no longer had good capacity. The battery impedance test
>> once a day, indicated it needed help. But it still behaved
>> like a 12V battery.
>>
>> The replacement lasted 3 years, and the chassis got warm on
>> the replacement battery life cycle. Measurement with a
>> meter later, indicated that half the cells had failed short
>> and it was then a 6V battery instead of a 12V one.
>
> I've noticed that the price of replacement batteries from the UPS
> manufacturer are terribly expensive.
> e.g. a 7AH 12v sealed lead acid Yuasa battery can be had for £15 or so.
> An (apparently) identical battery specified for a APC UPS is around £70.
>
> For domestic users, is there a good reason to pay the extra?

Short answer; probably not.

I have often noted that the APC packs use exactly the same make an model
of battery that I normally buy from CPC as a generic part. The
difference being they come a APC sticker! (and in the case of paks made
from multiple batteries they are already stuck together and have the
link wire and fuse fitted, so you don't need to remove that from the
last pack).

However, sometimes the official packs can be worth getting when you can
find them cheap enough, since they often include packaging and return
postage to recycle the old batts at their expense.

--
Cheers,

John.

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| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/

On 23/02/2024 10:20, Andy Burns wrote:
> Paul wrote:
>
>> Sometimes batteries jam in the tray or cavity in the unit,
>> and usually there are screws you can access, to release
>> the thing. I had to buy an extra-long screwdriver, just
>> so I could get the last duff one, out of the chassis. My
>> regular screwdrivers weren't long enough.
>
> This was the "best" example of that I ever encountered, the battery
> wasn't the correct type for cyclic use, the UPS was shoved in a hot
> cupboard
>
> <http://andyburns.uk/misc/APC_UPS_battery.jpg>

I pulled these sorry looking batts out of one of my old APC 1 kVA
BackUPS units in 2017:

https://wiki.diyfaq.org.uk/index.php/File:Wonkybatt2.jpg

(about 4.5 years of use)

They were quite toasty as well:

https://wiki.diyfaq.org.uk/index.php/File:Hotwonkybatts.jpg

--
Cheers,

John.

/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/