Question on expanding my pool

TrueNAS General
1

Hi, everyone,

I have a Truenas Scale (25.10.1 community) system set up with five 3TB drives in one pool. Recently, I purchased two 4TB drives to add to the pool. My question is, will this be a straightforward process (install the drives, expand the pool, on we go) or do I have to do something special to make it happen? As far as I know, the pool is the basic general ZFS pool without anything special done to it.

The data vdev has this for the stats: 1 x RAIDZ2 | 5 wide | 2.73 TiB for a total of 8.01TB currently. And it’s currently at 100% used space (I have backups that I can remove to free up space and possibly log files that can be removed as well).

Thanks for any information on this. :slight_smile:

Patrick.

2

Should be a straightforward process, however with a few caveats:

  • after expansion, free space calculation will be incorrectly displayed
  • only 3 TB of the 4 TB drives will be used
  • 100 % full for a ZFS pool is usually very very bad - so i dont know how the system is going to react to an expansion. Maybe delete or move 20%.
3

And keep in mind, you’ll have to extend the vdev one disk at a time, and it will take a while. The progress will only be visible via cli.

After expansion, you could use zfs rewrite -rvx /path/to/dataset/folder to recoup some space lost due to the expansion, but that also will take a while, and can’t be paused.

4

If this is mostly archive storage you could consider adding a 2x 4 TB mirror VDEV to the pool. Not perfect but perfectly viable.

5

So another question. I have the “Add to Pool” button and it shows 4 unassigned disks (two are 119GB SSD’s or NvME drives that were in the Freenas when I bought it and the others are my 4TB drives. They show as 3.64 TiB drives). Would I be able to use that to get the drives into my pool? After I free up some space, I mean.

Thank you and have a great day. :slight_smile:

Patrick.