Removing disks and pools

[KurtMan]

I'm new to TrueNAS, and running v13. No data is currently stored on the system.
I setup TrueNAS, and set the disk I'm using for the datastore. However, I decided to go another route with the disk, but can't figure out how to remove the former disk and pools. When I try to remove the pool I get an error it's in use. The disk is no longer in the system, but it still shows, while I can't locate the new raw, unformatted disk to pull that in and format it. When I search for the issue, lots of unrelated answers come up.

 

[Samuel Tai]

Look under System->Advanced for the System Dataset Pool setting. This is is set by default to your pool upon creation. Change this setting to your boot pool, and your pool will no longer be in use.

Then go to Storage->Pools, and click the gear. Select Export/Disconnect and check all the boxes to delete your pool.

Finally, go to Storage->Disks, and click the > on the right of your disk to expose actions for that disk. Click Wipe and choose the thoroughness of the wipe. Once the wipe finishes, you can pull the disk.

 

[67RS427]

Look under System->Advanced for the System Dataset Pool setting. This is is set by default to your pool upon creation. Change this setting to your boot pool, and your pool will no longer be in use.

Then go to Storage->Pools, and click the gear. Select Export/Disconnect and check all the boxes to delete your pool.

Finally, go to Storage->Disks, and click the > on the right of your disk to expose actions for that disk. Click Wipe and choose the thoroughness of the wipe. Once the wipe finishes, you can pull the disk.

Is a Wipe necessary? Just wondering as I set up a 6 disk pool to test and now going to install 14 disks and run a 2 vDev Pool of 7 disks each. I did have my disks filled with data about 50% full to test things out. Will a wipe help with fragmentation at all or does it even matter if I start all over fresh? Thanks!

 

[Samuel Tai]

You should perform at least a quick wipe to nuke the GPT partition table, because TrueNAS expects a bare drive without any partitioning when constructing pools.

 

[Treddit700]

How do I 'nuke' the drives if no longer see them? I did a fresh install of truenas scale 22.12 and no longer see my 3 harddrives since I didn't export/disconnect/wipe.. or whatever prior to the install. They are still there and I just want to wipe them so they show up and are viewable in the pool section. Currently my pool looks like the image below with the 3 harddrives not showing up in the list.
Thanks

 

[Treddit700]

Ok nevermind.. After I rebooted the system they eventually showed up and I just recreated the pool again even though there wasn't any data on the harddrives from the first time around. If you are curious below is what it looked like after the reboot.

 

[artlessknave]

You should perform at least a quick wipe to nuke the GPT partition table, because TrueNAS expects a bare drive without any partitioning when constructing pools.

there is no need to do this; it will cheerfully nuke everything on any disk you add to a pool. it will warn you before doing so just before creating the pool, and after the that the disks will be cleaned and used like they are new.
wipe is more for paranoia or to repurpose the drives completely (windows, sell them, recycle them, etc)

 

[NightFlight]

Am I right in understanding you can expand an existing pool with data on it, but not contract it?

 

[artlessknave]

not contract it?

contract?

Am I right in understanding you can expand an existing pool with data on it

this seems unrelated to the thread but yes, you can expand a pool with or without data on it, depending on a few factors, mainly the type of vdevs in the pool.

 

[rgorbie]

Am I right in understanding you can expand an existing pool with data on it, but not contract it?

You can "sorta" expand a ZFS pool, but maybe not the way you expect. Read this simple article. I ended up following the 2nd method because I didn't want to add another vdev:

How to Add a Disk to an Existing Pool in TrueNAS (2025) - WunderTech

This tutorial looks at how to add a disk to an existing pool in TrueNAS. There are a few different options, but learn which is best for you!

www.wundertech.net

 

[artlessknave]

those aren't "sorta", they absolutely are ways to expand a pool. the problem is that raidz vdevs are currently immutable.
there is code is development to change that though.