My pool has 6x 4tb hdd in RAIDZ2. For cold spares, I have 2x 6tb HDD, and 2x 4tb HDD not plugged in.
I realized with my setup now, it makes more sense to have 2vdevs of RAIDZ1 arrays or upgrade my current RAIDZ2 to have 8 HDD instead, and buy additional cold spares.
However, apparently you can’t upgrade your RAIDZ2 that way, so I’ll have to move the data somewhere, then back to it again. I have a little bit under 6tb of data in my pool right now.
I can easily scrap together a 4th gen i5 for under $30 so I can do a backup server using the 2 6tb HDD.
Would it be possible to back it up to a 2nd truenas server, destroy the old pool, make a new pool, and transfer it back? Would all my apps function the same? (I use Immich, Plex, and crafty)
It is now possible to “extend” a RAID-Zx vDev by 1 disk at a time. The process is not perfect, but does work with no data risk. You do have to be careful not to add the new disk as a new single disk vDev. People have been doing that for years, either thinking they were replacing a disk. Or before RAID-Zx expansion was available, adding the disk anyway, (as a single disk vDev).
I don’t have the exact GUI options memorized for RAID-Zx expansion, but it is in there somewhere.
It may make a difference on which TrueNAS base OS you are using, Core from FreeBSD or SCALE / CE from Linux. I don’t recall if TrueNAS Core supports RAID-Zx expansion.
Thanks for this! I’ll be including this youtube video from Lawrence Systems so others who stumble upon this post will have a clear solution on how to do this.
I was working with 2020 knowledge when I started using ZFS, so this is all very new hehehe
