grow raidz1 from 4 to 5 disks?

[PyCoder]

Hello

Im coming from Linux and I want to swap from OMV to FreeNAS but I have a question about zpools and raidz1.
In Linux (mdadm) it's possible to shrink, grow and even change the RAID level.

Can I do the same with ZFS?

I ask because I would like to start the (RAIDZ1) with 4 disks and then grow it to 5 disks.
I need that 5th disk to store my data temporarly and import it later into FreeNAS (ext3 import) on the existing RAID5 with 5 devices.
After I copied the data (ext3 import) I would like to add the 5th disk to the zpool so the RAIDz1 has at the end 5 instead of 4 disks.

Is that possible and how?

I tried to figure it out by myself but I wasn't able to do it in the WEBUI not in the shell.


PS: Yes I know shrinking isn't working.

 

[HoneyBadger]

There is currently no ability to change the size of a vdev in ZFS stable. What you are asking for is called "RAIDZ expansion" and it has been "in the works" for some time. I believe there is a very limited and completely not for production implementation in ZFSonLinux.

Short answer: No.

 

[blueether]

I believe that it could be done with a 'dummy' disk, but with raidz1 there is ZERO redundancy when you off line the dummy disk. You will also be distorting the 'back-up' of your data when you add the ext3 to the raidz1 array and then you have the semi-risky (because the disks are working hard) resilver process. - all in all I would put this in the too risky basket if you have important data.

Also concider that I don't think anyone recommends raidz1 anymore as there really is very little fault tolerance (once a disk is offlined to replace there is zero redundancy left). Most people seem to recommend raidz2

 

[PyCoder]

Oh, ok thanks :(

So that means I could make the raidz1 with only 4 disks, use the 5th disk to "transfer" my data from ext3 to zfs and leave it as a spare at the end. :/

Whatever.. thanks guys :)