Raspberry Pi SBC resilience

[Justin D]

I'm thinking of implementing a Raspberry Pi SBC to connect to our cloud based 3CX but I'm just wondering how they react to things like a power cut?

Do they just start automatically once power is restored?

Will they automatically reconnect to the remote 3CX if the router is slower at restarting and connecting to the internet?

Luckily we don't have many power cuts where we are (famous last words!), and it will be run from a UPS, but I just wanted to put my mind at rest as to the practicalities.

Thank you in advance for any input.

 

[Marari]

I'm just wondering how they react to things like a power cut?

Do they just start automatically once power is restored?

If it is connected to a UPS, you don't really need to worry about that as long as you check the battery once in a while and it's not a 'very' extended power outage.

Will they automatically reconnect to the remote 3CX if the router is slower at restarting and connecting to the internet?

Yes. It will keep retrying the tunnel.

 

[Justin D]

Thank you Marari.

if it was an extended outage and the UPS died, would the SBC restart automatically when the power came back up?

And is there any danger of corruption from an in-proper shutdown (as it's an SD card)?

 

[Marari]

Thank you Marari.

if it was an extended outage and the UPS died, would the SBC restart automatically when the power came back up?

And is there any danger of corruption from an in-proper shutdown (as it's an SD card)?

Without any sort of Pi-modding, the Pi will not come back up on its own after a power failure.

That said, please check out this: https://www.raspberrypi.org/forums/viewtopic.php?t=110332

You may find something of interest related to an external power bank and pin 5 ... I cannot verify the accuracy of the information however.

There is always danger of corruption on an improper shutdown. The above link also covers a hack to properly shutdown the Pi in case of power interruption using an external power bank.

 

[Justin D]

Thanks Ari, I'll take a look.

 

[pmterp]

Just wanted to share some experience.
If they are running Raspbian then yes, they will boot once power is restored and will automatically reconnect to the network once it is available.
SD Card corruption is a thing. Key tips are 1) don't use cheap SD cards as they are more prone to corruption and 2) keep them away from heat.
We've deployed dozens for small offices and have had 1 SD card get corrupted over the last year. However, the Pi was positioned on top of a PC case and between the modem and the wall. Once we replaced the SD card and repositioned the unit (with cable ties so it didn't get moved again), we've not had any issues.

 

[Justin D]

Just wanted to share some experience.
If they are running Raspbian then yes, they will boot once power is restored and will automatically reconnect to the network once it is available.
SD Card corruption is a thing. Key tips are 1) don't use cheap SD cards as they are more prone to corruption and 2) keep them away from heat.
We've deployed dozens for small offices and have had 1 SD card get corrupted over the last year. However, the Pi was positioned on top of a PC case and between the modem and the wall. Once we replaced the SD card and repositioned the unit (with cable ties so it didn't get moved again), we've not had any issues.

Thank you.

I was thinking of using a Samsung Evo or Pro card, in your opinion would that be a good choice?

 

[pmterp]

Thank you.

I was thinking of using a Samsung Evo or Pro card, in your opinion would that be a good choice?

We typically use Samsung Evo or SanDisk. I think it was a SanDisk that failed on us but I don't think I can blame that on the SD Card. In personal use I've ordered some cheap no-name cards and have had a much higher failure rate with those.

 

[Marari]

Thank you.

I was thinking of using a Samsung Evo or Pro card, in your opinion would that be a good choice?

Actually, I use a bit of a unique config.

I use the Pi Desktop which comes with a GPIO hat that allows you to use an mSATA drive. And yes, with a Pi 3b+ (or a Pi 3 with a roundabout hack), you can boot directly from the mSATA drive.

A lot less chance of corruption, in my opinion.

Here's the stuff (in $CDN)

Pi Desktop: https://canada.newark.com/webapp/wc...0001&urlLangId=1&langId=1&partNumber=05AC3756

Pi 3B+: https://canada.newark.com/raspberry-pi/2773729/sbc-arm-cortex-a53-1gb-sdram/dp/49AC7637

Official Pi Power Supply: https://canada.newark.com/webapp/wc...10001&urlLangId=1&langId=1&partNumber=77Y6535

(I always recommend using the official power supply with model 3b or 3b+ because I never get the low voltage warning using the official power supply).

32 GB mSATA drive: https://www.amazon.ca/TCSunBow-Capa...F8&qid=1538057169&sr=8-7&keywords=32+gb+msata

All said and done, this little rig is about $142 CDN (about $110 US).

 

[pmterp]

Actually, I use a bit of a unique config.

I use the Pi Desktop which comes with a GPIO hat that allows you to use an mSATA drive. And yes, with a Pi 3b+ (or a Pi 3 with a roundabout hack), you can boot directly from the mSATA drive.

A lot less chance of corruption, in my opinion.

That's a great setup. Thank you for sharing.

 

[Marari]

That's a great setup. Thank you for sharing.

My pleasure.

If there's enough interest in it, I might even put together a step-by-step config guide to making it all work.

 

[Justin D]

Thank you for sharing that setup, I wasn't aware of the Pi Desktop case!

 

[Marari]

Thank you for sharing that setup, I wasn't aware of the Pi Desktop case!

I stumbled across it by chance and since buying one, it's all I buy for Pi cases anymore.

 

[kraichle]

R-pi's are so cheap I just bought a second one and made a copy of the SD card for it. If there's any issues, I'll just switch it out. Its only two wires. Anyone could switch it out. We have a small office of ~10 and if there's any network/phone issues I always have them power cycle all the hardware including the R-pi, modem, router, swtich, etc. Never had a problem yet in a couple years, and it's been cycled a bunch of times. I may have config'd it to auto boot when I set it up, but not sure, but it works fine every time.

 

[Wendelspanswick]

Without any sort of Pi-modding, the Pi will not come back up on its own after a power failure.

That's not correct, if you pull the plug on a Pi, then re-apply the power it boots up and runs as normal.

There is also a setting under Pi preferences "Wait for network before boot".

 

[Marari]

That's not correct, if you pull the plug on a Pi, then re-apply the power it boots up and runs as normal.

There is also a setting under Pi preferences "Wait for network before boot".

With the pi-desktop it's a little bit different as there is an actual power button and scripts to make it function properly.

That said, it's still a good idea to hook up the pi to a UPS.

 

[Lee Cramman]

With the pi-desktop it's a little bit different as there is an actual power button and scripts to make it function properly.

That said, it's still a good idea to hook up the pi to a UPS.

A power-bank that puts out enough amps for the RPi would be a cheap UPS...

 

[Marari]

A power-bank that puts out enough amps for the RPi would be a cheap UPS...

Yep. That would work too.

 

[AGidi]

We have short of a dozen working. The power bank "UPS" trick is nice, im going to test it for SMBs or sohos that dont have a UPS.