Quick question on a new VDEV 1 of the 4 1TB disk is 20GB smaller. Is ok to force?

[calmasacow]

I have 4 nvme ssd that are 1TB disks.
3 are samsung @ 953.87GiB
1 is saberent @ 931.51GiB
trying to put in to a RaidZ vdev. I get a warning about not being recommended due to the Saberent drive being smaller by about 20GB.

is it ok to force? is there risk of data loss?
if all it means is that it will just use only 931.51GB of all of the disks to match the smallest one then I'm totally fine with that.

thanks in advance.

 

[Ericloewe]

Look, there's nothing to force. It either works or it doesn't, and 20 GB is well beyond the margin you might be able to manually play with. If you're lucky, it's small enough a difference to work out (due to details of how ZFS space management works).

is there risk of data loss?

No, but I doubt this would work.

if all it means is that it will just use only 931.51GB of all of the disks to match the smallest one then I'm totally fine with that.

No, you cannot reduce the size of a vdev.

 

[danb35]

Look, there's nothing to force.

There is in current versions; the UI will refuse to create the pool/vdev unless you "force" it.

trying to put in to a RaidZ vdev.

If you're trying to create a new RAIDZ vdev, yes, it's safe to override this warning.

 

[Ericloewe]

There is in current versions; the UI will refuse to create the pool/vdev unless you "force" it.

Apologies, poor choice of words. It's more accurate to say that the process of trying to replace a disk with a smaller one is harmless if it doesn't work and uncontroversial if it does work.

Wait, are we talking about a new vdev? How did I completely misread this? Yes, you can just use a slightly smaller disk as part of a new vdev and you'll just lose the little bit of capacity.

 

[calmasacow]

weird thing I tried and confirmed and everything but the final create button would never work. anyway thinks for the answers. I ended up going and backed up the data off a system that had a compatible drive and swapped them out it is working now. turned it was one of the Samsungs that was the offender. 970 plus was 20GB smaller than the 2* 970 Pro drives. so grabbed and now it is 2 sabarent and 2 Samsung 970 pro. all exactly the same size.