Comment on TrueNAS Scale, hard disks, and pools
bigredgiraffe@lemmy.world 1 day ago
Okay so when you say “unplug the power” do you mean shut it down first or just pull the plug? The latter is a great way to corrupt your storage pools as ZFS uses memory for read and write cache etc by default. You definitely need to do a graceful shutdown especially if there is data that was recently written to disk, that’s why a UPS is so recommended. That said you can usually import an existing pool when that happens, I think there is a UI menu for it now.
Flamekebab@piefed.social 1 day ago
The hard disks are on a separate power supply. The TrueNAS software is running on an old laptop so it effectively has UPS protection.
bigredgiraffe@lemmy.world 1 day ago
Okay so the disks aren’t also on UPS? That might actually be even worse than the whole thing getting turned off, ZFS is definitely not meant to be run on removable disks like that.
Flamekebab@piefed.social 1 day ago
Haha, yeah. It does make me wonder whether I should bin the whole TrueNAS approach entirely. It seems like a tremendous faff when I could just have the files mirrored to another disk as a backup.
4am@lemm.ee 1 day ago
If you shut down the computer gracefully first before you power the disks off of should be ok more often than not, but you really should try to have everything on the same system so this can all be coordinated by the OS and the hardware.
As others have said, avoid powering the disks off before the OS has had a chance to shut down or your disks will NOT be in a recoverable state when everything comes back online.
I’m not even sure the setup you are describing would benefit at all from a different storage method, even “regular” writes could be in memory or controller buffers. External drives are not meant to have their power cut.