Hi!
Yesterday, I expanded a RAIDZ volume composed by three drives of 10G each adding a vdev composed by another three drives. These drives have 20G each.
I was surprised when I get 60G of storage. I've just lost a 33% because of parity.
I've said, I was surprised because I thought that you cannot expand a RAIDZ with different sized drives, or better said, you can but I thought that in the concrete example I put, I would only get 40G of storage, because the original RAIDZ was composed by 10G drives.
So, assuming that you only lose storage necessary for assuring parity when you expand a RAIDZ, indepedently of the overall storage of the new vdev, I would like to ask you:
- What are the drawbacks of that scheme? Performance, maybe?
- How many drives can fail and where, before I lose data?
Thanks in advance
Yesterday, I expanded a RAIDZ volume composed by three drives of 10G each adding a vdev composed by another three drives. These drives have 20G each.
I was surprised when I get 60G of storage. I've just lost a 33% because of parity.
I've said, I was surprised because I thought that you cannot expand a RAIDZ with different sized drives, or better said, you can but I thought that in the concrete example I put, I would only get 40G of storage, because the original RAIDZ was composed by 10G drives.
So, assuming that you only lose storage necessary for assuring parity when you expand a RAIDZ, indepedently of the overall storage of the new vdev, I would like to ask you:
- What are the drawbacks of that scheme? Performance, maybe?
- How many drives can fail and where, before I lose data?
Thanks in advance