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Comment by ocius | Hacker News Reader

Depending on your write load, the SD card could become a problem, but you could mount a USB SSD. You can even boot from a USB SSD now (https://www.makeuseof.com/how-to-boot-raspberry-pi-ssd-perma...)

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Anyone know what the best practice is to guard against corruption on your SD card or your SSD if your home power goes out and your Raspberry Pi power-cycles unexpectedly (outside of just getting a UPS?)

I've had a previous RPI SD card get corrupted this way and I've been hesitant to do anything useful with home-hosting on one since I had that problem.

The only things I can think of do involve a ups. There are battery banks that support pass through charging but I’m not sure if you’re supposed to use that constantly. A low capacity power strip style ups seems like the next best. Or don’t use a pi at all - if you have an old laptop that you don’t use, that could be the server and it has its own built in ups.

Sorry I don’t know that I’m being helpful here. I had the same issue and just ended up with an ups - but I also ended up plugging my networking rack into it (router, cable modem, switch, nas) as well. We’ve only had one real outage since I set this up, but it kept my network alive for 90 minutes or so and then the power came back up.

Backup, backup, backup.

Also test your backups.

Get an SD card specifically labeled "high endurance." They're a tad bit more expensive, but do work.

Corruption has always been an issue with using standard SD cards as a boot system. It's just something these cards were never meant to do. I run multiple Pis at home, one of them as a scraper/site hosting/MariaDB/Wireguard. Power outages would almost always corrupt the file system, and a few times, damage the SD card. Once I switched to high endurance cards, I haven't had a problem.

I have a datalogger based on RaPi running since around 2 years. It writes every 5 minutes more or less 25 bytes to a file on a standard SD card. I have frequent black outs (and maybe brown outs, too, but never investigated this), and I never had problems with FS corruption.

A good alternative is to use a similar SBC with eMMC module support, such as one of the ODROIDs

I have a Toradex Colibri with 4GB of eMMC formatted with ext4. As part of a system test I've been cutting power on it every 12 hours for two years now and haven't lost a byte.

Enable read-only overlay for your rootfs and make your /boot readonly. Just use raspi-config, and go into performance options.

There are some gotchas - everything you write after that goes to a tmpfs. Meaning it starts cutting into your available RAM. So this overlay is only really useful if you are using the high-memory variants like the 4GB/8GB RPI4. With the 1GB Pi variants, this gets painful.

Alternatively, You could setup a cron job to reboot every night thus clearing the tmpfs.

Do remember to disable the overlay (and make /boot rw) every few weeks to apply updates.

Or use tmpfs for things that get written, but actually don't need to be persisted.

These days 'overlayfs' I think[1], though if you're running nginx on there to serve a site/app you might want logs?

1: https://forums.raspberrypi.com/viewtopic.php?f=63&t=253104&p...

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