Freenas - Expanding volume

We currently have a server with 5x3TB disks configured as a RAIDZ:

zpool status
pool: raid-5x3
state: ONLINE
scrub: none requested
config:

NAME                                              STATE     READ WRITE CKSUM
raid-5x3                                          ONLINE       0     0     0
  raidz1                                          ONLINE       0     0     0
    ada1p2                                        ONLINE       0     0     0
    replacing                                     ONLINE       0     0     0
      ada2p2                                      ONLINE       0     0     0
      gptid/a767b8ef-1c95-11e2-af4c-f46d049aaeca  ONLINE       0     0     0
    ada4p2                                        ONLINE       0     0     0
    ada5p2                                        ONLINE       0     0     0
    ada3p2                                        ONLINE       0     0     0

errors: No known data errors

We want to add 5 more 3TB disks into the same machine, and enlarge the current volume ... is that possible?

I am still confused by the terminology -- vdev/zpool/volume/dataset -- want to make sure I do it right.

As I understand it, I will need to make a new RAIDZ out of the 5 new disks -- is that a vdev? Then add that vdev to the current pool, and we will end up with 10x3TB - 2x3TB = 24TB of storage, where each set of 5 disks can sustain 1 disk failure.

Just not sure what the exact steps are to do this !

Also -- not sure why zpool status still says "replacing" -- it's been like that for several weeks, since I replaced a disk with a hot spare. Is it safe to remove the old disk now?

Thanks!

You cannot increase the size of a vdev by increasing the number of disks (yet, but that feature probably won't be added for at least a year) (you can increase the size of a vdev by increasing every drive to a larger drive)

You can add a second vdev as a raidz1 with the 5 new disks in it, and add that vdev to the same zpool.

If you're using the FreeNAS GUI, this is all done in the Volume Manager take note of the "Extending a ZFS volume" section.

Your use-case is pretty straight forward, select the volume (zpool) you want to extend, then choose the layout (raidz1) and all 5 disks with "add new disk"

FreeNAS uses the term Volume and zpool relatively synonymously. (which is kind of confusing because of zvols)

You may find this presentation useful.

I just noticed, that you named your zvol "raid-5x3" this will no longer be accurate, I suggest changing it to something nondescriptive of how it's setup. At home my zpool's name is "storage" at work we call it "acquifer", it's unusual to have multiple zpools on the same NAS, so call it whatever.