Using HDD's for ZFS: 'desktop' vs 'raid / enterprise' -edition drives?

[Frederique Rijsdijk]

After some reading, I come back from my original idea. Main reason is 
I'd like to be able to grow the fs as the need develops in time.

One could create a raidz zpool with a couple of disks, but when adding a 
disk later on, it will not become part of the raidz (I tested this).

It seems vdevs can not be nested (create raidz sets and join them as a 
whole), so I came up with the following:

Start out with 4*1TB, and use geom_raid5 to create an independent 
redundant pool of storage:

'graid5 label -v graid5a da0 da1 da2 da3'  (this is all tested in 
vmware, one of these 'da' drives is 8GB)

Then I 'zpool create bigvol /dev/raid5/graid5a', and I have a /bigvol of 
24G - sounds about right to me for a raid5 volume.

Now lets say later in time I need more storage, I buy another 4 of these 
drives, and

'graid5 label -v graid5b da4 da5 da6 da7'
and
'zpool add bigvol /dev/raid5/graid5b'

Now my bigvol is 48G. Very cool! Now I have redundant storage that can 
grow and it's pretty easy too.

Is this OK (besides from the fact that graid5 is not in production yet, 
nor is ZFS ;) or are there easier (or better) ways to do this?

- So I want redundancy (I don't want one failing drive to cause me to 
loose all my data)
- I want to be able to grow the filesystem if I need to, by adding a 
(set of) drive(s) later on.



-- FR