Sharing a recent experience that might help others.
- Don't panic. Unless your drive is clickety-clunking and you don't have offline/offsite backups of the important stuff.
- Don't use 8yr old drives.
- Spend the couple of minutes it takes to configure notifications
- Knowing how to use dd or ddrescue, mount and xfs_repair can save the day.
Had an old (8yr) 750gb drive disappear from its slot in the array. I power cycled, still not there but the disk appeared in unassigned devices. I mounted it from there to check its contents. Empty. SMART report showed a bunch of ba