Adding and remove mirrored vdev in scale

[sybreeder]

I'm testing in virtual environment adding and removing mirrors and it seems to be working
I 2 mirrors

I'll click remore second mirror. There is no error.
pools is still online, share with test file is still online.
So as long as free space on the pool is lower that lowest mirror it will be possible i'm assuming ?
If data is scattered on all mirrors during remove vdev it will be rebalanced to mirrors that was left untouched ?
is such adding and removing mirror vdev is now safe?

 

[HoneyBadger]

Hey @sybreeder

You've got it correct on all fronts - as long as you have sufficient space in the remaining vdevs you can remove mirrors or stripes.

Note that this only works for pools with only mirror or stripe vdevs - you cannot remove a vdev from a pool if a RAIDZ vdev exists.

 

[sybreeder]

Hey @sybreeder

You've got it correct on all fronts - as long as you have sufficient space in the remaining vdevs you can remove mirrors or stripes.

Note that this only works for pools with only mirror or stripe vdevs - you cannot remove a vdev from a pool if a RAIDZ vdev exists.

That's awesome! Thank you
Another reason why mirrored is way better for expansion
So if i don't have sufficient space on pool will i get error and vdev removal will not be possible ?

 

[HoneyBadger]

So if i don't have sufficient space on pool will i get error and vdev removal will not be possible ?

Correct; you'll get a pop-up dialog stating that there isn't enough free space left in the pool, and the removal will be cancelled immediately.

 

[Whattteva]

Hey @sybreeder

You've got it correct on all fronts - as long as you have sufficient space in the remaining vdevs you can remove mirrors or stripes.

Note that this only works for pools with only mirror or stripe vdevs - you cannot remove a vdev from a pool if a RAIDZ vdev exists.

I presume this process can take several hours if the vdev you are removing has decent amount of data that has to be migrated to the other remaining vdev?