increasing available space

[urobe]

Hey there,

I have a freenas running with 10x4tb hdds all in one pool, raidz3. In this Pool I created a single dataset. There is a second system, exactly the same, serving as a backup.

Because it works so well, and is being used heavily, also for backups of Desktop computers, the space is filling up a little quicker then we anticipated.

My understanding is that I have two options now, replacing existing drives with larger ones, or adding a second pool, identical to the first one?

My idea was, but I'm not sure if thats possible, to do one way for the working system, and the other for the Backup?

First I would have replaced the disks on the backup with 10x8tb drives. Which should double my capacity?
Second, I would have taken the 10x4tb drives from the Backup, and added those to the working system. The working system is only a dataset, not a zvol.
Does the working system have to fulfill any requirements to be able to double the number of disks?
My understanding is, that if either pool fails, all data is gone. But with the backup and twice 3 times redundancy, I think this is an acceptable risk. or would it be better to create a new pool including all 20 disks? Downtime is possible.
I wanted to double the number of disks of the working system, as I thought it would even further improve performance?

Any thoughts are greatly appreciated!
-Tobi

 

[garm]

My understanding is that I have two options now, replacing existing drives with larger ones, or adding a second pool, identical to the first one?

What makes you think that?

My understanding is, that if either pool fails, all data is gone.

No, that is not how it works.

I wanted to double the number of disks of the working system, as I thought it would even further improve performance?

Biggest performance factor is number of vdevs. One single large raidz3 vdev is slower then two raidz2 vdevs. You need to weigh cost performance with risk. In an enterprise setting I would not tough the system unless I could add new vdevs. If you plan on replacing more then a few disks I would buy a new system with larger capacity and migrate the old server to the new.