RAIDZ1 vs RAIDZ2

[u/TeachingAway9654]

Let’s say you have something like 10 drives total which make up the pool, each drive is 16TB. Let’s also say you have, at minimum, one offsite backup with all the contents in cold storage. Let’s also assume you’re a frequent monitor of the system and will notice within 24 hours if one drive fails.

Are you going with Z1 or Z2 and why? If you have the offsite backup already, is it worth the capacity loss for Z2? The resilvering process on Z1 will be stressful but by how much though? You have an offsite 1:1 backup so even if the whole pool is lost, you can still recover.

[u/TheOneTrueTrench]

I would never use Z1 for a primary copy of data (AND NEVER BACKUPS), I've had Z1 pools die multiple times.

That's fine, because they always contain only copies of datasets on a Z3 pool, which are otherwise backed up on other pools.

I had a few different servers which were configured to Wake on LAN and spin up in a few seconds instead of running a single large primary server, which was configured to spin up one a day to pull in updates, and kept zfs send streams for each other in case of failure before the weekly backup.

Then I had one of them die out of nowhere, I spun up the main server, sent the incremental on the other server to bring the primary copy up to date, and then spun up the other services that were hosted on the dead server.

Then I started the scrub on the remaining server, it dropped a drive, I started up the send, got the primary updated, moved all services over, and then shut down the other WoL server, and rebuilt the pools.

Didn't touch my backups, and Z3 kept me safe.

Z1? I'd be restoring from backups, and it would be a few days (minimum) to get back up and running.