It’s not good to power off a mounted drive. At least for the file system. I don’t know about the drive itself.
Comment on How to auto remount external HDD after power loss to laptop server?
Lenna@piefed.ca 4 weeks agoThis is my HDD. Aren’t these guys able to handle power losses since people usually plug them in to backup stuff, and then pull the plug once they’re done?
And does ext4 count as a journaling file system?
chris@l.roofo.cc 4 weeks ago
Natanael@slrpnk.net 4 weeks ago
It counts as long as barriers are on
https://archive.kernel.org/oldwiki/ext4.wiki.kernel.org/index.php/Ext4_Howto.html#Barriers_on_by_default
External drives expect you to ensure writes complete first. If you don’t then smart software with copy-on-write and consistency checks can survive power loss (at the cost of losing recent changes). Other software which assumes a reliable drive can get wrecked.
Lots of file systems can not handle random power losses because they don’t force continous integrity of the disk file system, that’s why FAT formatted drives so often get corrupted