Ideal Disk Layout?

[Truenigma]

I'd like some opinions regarding the ideal disk layout in my most recent build.

I have a 24-bay chassis, 3x drive controllers capable of 8 drives each. and 24x 1TB sata drives. My initial config is 4x vdevs of 6xdrives using 2x drives on each controller in raid-z2. My thoughts are this allows me to upgrade the disks in smaller numbers 6 at a time, also gives me a great deal of redundancy with raid-z2 and using 2x drives per controller I could actually loose an entire drive controller and the system would remain viable until I replaced the bad component.

My concern with this layout is it does waste a lot of storage, out of 24disks I loose 8 to parity drives. I'm torn between redundancy & space, not very concerned about performance.

Appreciate any suggestions or comments,

Truenigma

 

[Ericloewe]

If you're paranoid about controller failure, go ahead, but it won't make a realistic difference.

If you want to use a lot of drives, you obviously need a lot of parity drives, there's no way around it if you want to stick to the recommended vdev sizes.

 

[toadman]

I would have suggested the same 4x 6-drive RAIDZ2 vdevs that you thought of originally. Pretty much any other config that gives you more usable space is going to have less vdevs. So your iops would drop (which may or may not be an issue depending on workload).

The only other config I could potentially see using would be 3x 8-drive RAIDZ2 vdevs.

I would not use RAIDZ1 at all.

 

[Ericloewe]

I would have suggested the same 4x 6-drive RAIDZ2 vdevs that you thought of originally. Pretty much any other config that gives you more usable space is going to have less vdevs. So your iops would drop (which may or may not be an issue depending on workload).

The only other config I could potentially see using would be 3x 8-drive RAIDZ2 vdevs.

I would not use RAIDZ1 at all.

3x 8-drive RAIDZ2 would work, at the expense of performance, particularly for random workloads.