Back when I was even less experienced in self-hosting I setup my media/backup server using a RAIDZ1 array and 3 x 8TB disks. It’s been running well for a while and I haven’t had any problems and no disk errors.
But today I read a post about ‘pool design rules’ stating that RAIDZ1 configurations should not have drives over 1TB because the chances of errors occurring during re-silvering are high. I wish I had known this sooner.
What can I do about this? I send ZFS snapshots to 2 single large (18TB) hardrives for cold backups, so I have the capacity to do a migration to a new pool layout. But which layout? The same article I referenced above says to not use RAIDZ2 or RAIDZ3 with any less than 6 drives…I don’t want to buy 3 more drives. Do I buy an additional 8TB drive (for a total of 4 x 8TB) and stripe across two sets of mirrors? Does that make any sense?
Thank you!
Those failure rates are nonsense based on theoretical limits. In practice: a few weeks ago I resilvered a 4 disk z1 array with 8tb disks at 85% capacity in less than 24 hours. I scrub the pool every month and it didn’t seem any more taxing than a scrub.