Suche USV für einen RPi4

That's a bit odd. I am fairly sure that the only things that don't restart are my desktop PC and big *86 based server, because I have configured them not to. My Pi comes up OK

Why? Because back in the day, I used to let them auto boot on power on and one day, we have a power cut, followed by a power on, which started a boot, followed by a brownout that chopped power to the companies main

Never got that back.

hard earned lesson. Most *nix machines will survive a power cut. Mysql and so on may need repairing, but that's what transaction files are for. But no *nix machine that experiences a power cut and restart *in an active fsck session* is likely to make it.

I wait until the power is back on for a time before I hit the tit.

Indeed, but having the UPS tell the the server to shut down cleanly it its battery gets exhausted would save a certain amount of dosh when it comes to replacing UPS batteries: running an SLA flat and not recharging immediately is not good for them.

FWIW, my experience would seem to show that the UPS battery, on my rig anyway, has a very easy life. As I said, its initial set of batteries (Yuasa 7AH SLA) lasted for 8 years. I also use a pair of YUASA 7.2 AH to run the instruments, radio and FLARM in my glider. They get charged after each flying day and are cycled to measure their capacity every year. They get slung when their capacity drops below 65% of the rated value: generally this means they get replaced every 3 years.

He might get away with that reasonably cheaply if he's using alkalines or small SLA batteries, but other rechargeable battery types don't like being run flat and left, so could get both annoying and expensive without the backstop of a full shutdown when the UPS batteries are empty.

This is one reason why I suggested the Pi hat type UPS: most of these can shut the Pi down cleanly when the battery is exhausted.

Interesting: thanks for the info

Indeed. I do exactly that with my house server: I use a cycle of two of WD Essentials 1TB USB drives to maintain backups of it.

One of the older parts of Harlow, the first postwar New Town.

Could you describe in more detail exactly what happens?

That's very unlike the behavior of my system, which runs Linux raspberrypi 5.10.103-v7l+ #1529 SMP Tue Mar 8 12:24:00 GMT

It's been crashed innumerable times by pulling the wrong plug, plugging in extra USB devices and software screwups. It's never failed to come back up to multi-user on its own.

It sounds as if your machine is heavily loaded, set to cache storage writes very aggressively or configured to halt restart on minor errors. There were reports of lack of a monitor causing startup troubles but I don't think that was with RasPiOS.

It's certainly true that a UPS will help, but it isn't clear that's the root of the undesired behavior.

HTH,

bob prohaska

I was thinking of something much simpler, a delay timer that waits a while before powering the Pi back up. Just how long to wait will be a guess, somewhere between a few minutes and a few hours depending on the behavior of the power company. However, it'll only help if the root problem is interrupted restarts. That isn't certain at this point.

If you can avoid peaky loads lead acid isn't bad. The refrigerator is what got me into trouble with deep cycle lead acid. For the Pi it was ok. But in general, LiFePO4 outperforms lead, at higher cost..

For the OP I think you're right.

^^^^^^^ Oops, bad wording. Should have said "back up power".

Still true, as always!

bob prohaska

Well I don't live in as New Town. I live next door to a property mentioned in the Domesday book... Not much has changed here since the 1920s, except broadband, which has gone all fibre

It doesn't matter how much undergrounding is done when the main trunks are above ground

And vulnerable to lightning strikes, or, the lines - like the old man of Madras' balls 'in windy weather they clashed together, and sparks flew out of his arse'.

Even in towns its usual for substations to be fed from overheads. 33kV or 66KV. Only Londo undergrounds it's special 22KV network

"National Grid owns the high voltage electricity transmission system in England and Wales and operates the system throughout Great Britain at

So the very high voltage stuff is predominantly up in the air

As is most of the intermediate 11, 33 and 66kV stuff

BUT it is possible that large towns will get a 175vKV feeder direct into a substation and then the down conversion to domestic voltage is all done there.

Sounds like your SD card is past end of life. Either get a new one, or use an alternative boot device such as a USB stick, or better still a small SSD with a USB adaptor.

---druck

Indeed.

Its possible that Harlow originally had above ground wiring,but somehow I doubt it: ads I said already, I live in one of the first bits of Harlow to be built, in a terrace which was built on a concrete slab with 13" no- fines, no cavity walls and with water, gas, and mains all in the base slab and originally with single pane iron framed windows, which were replaced with double glazing over 40 years ago. The only visible wiring is phone lines run just under the eaves, and would almost certainly have been installed some years after after the terrace was occupied.

From this I deduce that the mains lines in this part of Harlow have always been under the concrete pavement at the front of the terrace along with the water mains.

So, as I said, mains drop-outs either take out large chunks of the town for minutes to hours and are roughly once per decade events.

The rest typically last for milliseconds to (rarely) 30 secs to a couple of minutes and tend to affect a relatively small part of town.

These are what I bought the UPS to counter and I only got it because the glitches were frequent enough to be annoying. Needless to say they've not been anything like that frequent since I installed it, but at least I not have a better understanding of what a UPS can and cannot do and what features are worth paying for (multiple power supply sockets, the ability to:

- shut the server down after a preset time or when its battery is empty,

- to report UPS activations and battery condition warnings to the server.

If there weren't bloody great Council-owned oaks immediately south of the terrace I'd have fitted solar panels for both power and hot water. There's just enough south-facing roof area to make the combo practical if the oaks weren't in the way and the terrace is aligned almost due east-west.

Am 21.12.22 um 21:55 schrieb druck:

In the past you are right. I have destroyed some SD-Card because of

We are talking about slightly different things here. In general except in the very rural places (like here) , the last mile is undergrounded. You will be connected to a substation serving a few thousand customers, which will push out 3 phase 230/415V stuff under the ground. That substation will be fed with a high voltage part of the grid, typically overhead. The current trend is to have all new stuff below 33KV undergrounded, but out here, we have overhead 11kV single and three phase lines, and the substation is a one or two property serving transformer up a pole. Except down in the village center, where there is a big grey hummy thing fed from the 11KV that serves all the concentrated houses , some undergound and some from poles.

I have my own (private) grey hummy thing fed from the 11KV I paid a huge amount to have undergrounded.

So it didn't run across my back garden

What is common depends on where you are. Almost all of London is undergrounded now right up to pretty high voltages.

Alamost all of Rural Suffolk is overhead, right up to the houses eaves. Only te towns and larger parts of large villages are undergrounded, and even then it is vulnerable to lightning strikes, wind induced shorts and tree branches as it is all fed from overhead 11 and 33KV rings

It may be current practice to have nothing new below 100KV run overhead, but there is a heck of a lot of legacy grid out there that the power companies cannot afford to replace except slowly as and when. When I asked to get my section undergrounded the engineer who organised and planned it said 'We are not putting in new 11KV overhead, but I only have a limited budget to underground existing ring segments, nut if you can come up with £18k I'll match that and do the job '

Since it probably added £200k to the value of the land, I wasn't too upset...

Am 22.12.22 um 07:17 schrieb The Natural Philosopher:

I'm not sure about that. In the past running a P1 on SD-Card. The SD-Card is destroyed several time because of running 24/7. An other Pi I used for XBIAN and running on SD-Card only, I switched off by accident without a proper shutdown. It results in a corrupted FS, too.

On this Pi the /boot is vfat (rw, relatime, shortname=mixed, errors=remount-ro) and / is ext4 (rw, noatime, discard and with journal enabled). Set via tune2fs to -c 1 -i 1d.

In my opinion it is unsafe to power off the Pi without a proper shutdown regardless it is running on SD-Card or USB.

He's right: he's saying leave the vfat (boot) partition, on the sd card and move the ext4 partition (everything else) to usb-attached storage.

This way the SD card is *always* read-only unless you're updating the vfat boot partition , which is a rare operation, and all normal writes go to the ext4 partition, which can be on ssd or spinning rust.

Well yes, nothing is guaranteed, but my Pi has always booted after a power cut and that seems to be the general experience. Your experience seems unique

Well I tested on an rpi3.

The rpi3 did run off a powerbank which was isolated from the mains.

The rpi3 also ran off a powerbank which was itself connected to the mains. However, the rpi3 still switched off when the mains power supply to the powerbank was switched off. So the whole idea of using this as a cheap UPS is a non starter.

Who knows if that would be the same for all powerbanks?

I also did not get a reliable low voltage warning when the powerbank ran down (when not connected to the mains). The rpi3 just switched off. Maybe I messed up the test, but given the overall solution didn't work as intended, I can't be bothered to investigate further.

It was for the one I used (no longer available), but you would need to check any you bought. It was only ever intended for a short outage cover.