First steps on troubleshooting crashes for aheadless pi?

Question

I use a Raspberry Pi 4 8 GB as a headless server to run stuff like pihole, nextcloud, wireguard, etc

Ever since I switched from booting and operating from an SD card to an external SSD drive over USB, I find it crashes quite more often (once or twice a week with the SSD vs just me physically crashing into it and unplugging something with the SD card)

What would be the first steps in troubleshooting this issue? Any logs I could check upon boot up to see if I'm having a power issue or if some service is hanging the pi or something like that?

Answer 1

I'd start by checking the PSU rating is enough for worst case Pi and SSD simultaneous current draw. I've seen many problems where random reboots are due to under rated PSUs, especially with external disks.

The particular "fun", is that you can have a system which works fine most of the time, but when you get an unfortunate combination of CPU usage and disk activity, the increased power draw causes the voltage to drop and the system to reboot.

Update: I had exactly this problem yesterday when trying to swap to a new SSD for a large database. The original had worked fine for three years, but I could just not get the copy to work, with the target persistently unmounting and remounting read-only. Added a powered hub, and I was done in under 20s. And with just the new disc, all seems stable. Current draw of both was simply too high...