Upgrading original Volume with larger drive capacity

[RonRN18]

I first built my NAS about 6 or so years ago. My original volume was a RAIDZ-1 with four 3-TB drives. I am wishing to upgrade this volume with, probably, 6-TB drives. I don't want to lose any of the data or have to change any significant settings and curious how to do this in the best fashion. Can I re-silver one 3-TB drive with a 6-TB drive, one at a time and then take advantage of the double capacity? I have only re-silvered drives when there was a failure, not when I was wishing to upgrade. I just get anxious anytime I mess with this and want to make sure I do my homework and know what to expect before I do.

This machine has been somewhat of a "Winchester Mystery House" of a NAS. All of my volumes are in four-drive RAIDZ-1 arrays. I know it could be done more efficiently with more drives per volume, but I can only justify at certain price-point increments. The first volume is four 3-TB drives, the next two volumes are four 4-TB drives each. The fourth volume is four 6-TB drives. My hope is to upgrade Volume 1 to four 6-TB drives without losing data or having to make numerous changes elsewhere. I still have capacity in the machine for four more drives after that, but I'd rather have migrated the first volume to larger drives first.

 

[NugentS]

If you have spare drive slots then the best way is to build your new pool and the ZFS Send | ZFS Recv the data between the pools - and you appear to have spare slots

If not then swap out one drive at a time until you have swapped the entire vdev at which point you can expand the array into the extra space.

Swapping one drive will do nothing, you have to swap all drives in the vdev, one at a time and then resilver - which is boring AND stressful on the array.

 

[sretalla]

Since you're RAIDZ1 here, I would recommend doing the replace without removing any of the original drives if it's at all possible. If you remove/replace/resilver, you're going to be without redundancy for the whole operation, so an unexpected drive failure will toast your pool.