Options for growing a pool with differente native block size disks (1TB to 3TB disks)

[Rodrigo Cesconeto]

I followed the instructions for growing a ZFP Pool (https://doc.freenas.org/9.3/freenas_storage.html#replacing-drives-to-grow-a-zfs-pool) using an extra SATA port.

However, after replacing a 1TB disk with a 3TB one, zpool status warns me about different native block size of the new disk (4096b) from the configured pool block size (512b). I tried to find out if it was possible to change the pool block size but I didn't find anything encouraging.

I reverted the change, and put back the original 1TB disk in the pool.

The machine has two RAIDZ1 pools:

Pool A has 3 x 1TB disks
Pool B has 3 x 2TB disks​

I have 2 free SATA ports.

The only thing that comes to my mind is to destroy Pool A, create a new one with the 3TB disks, recreate the datasets and restore the backups. Is this the best option? Any other ideas?

Thanks fort any help.

 

[Bidule0hm]

You can't change the block size once the pool has been created.

The best option would be to create another pool and use ZFS replication (so you don't have to recreate the dataset and co manually), IIRC @depasseg made a great thread about doing that ;)

 

[Rodrigo Cesconeto]

The problem is that I don't have enough free ports to create a new pool without destroyng Pool A.

Unless I bring down Pool B while I move the data. Is there anyway to do that safely?

 

[Bidule0hm]

Yep, you can detach the other pool while you do the move. There's a button in the GUI but be careful and read the manual about detaching a pool (http://doc.freenas.org/9.3/freenas_storage.html#view-volumes) because you can erase the drives if you don't know what you're doing.

NB: RAID-Z1 with drives bigger than 1 TB isn't recommended (see the link in my signature if you want more infos).