ZFS confusion

[Kaya Saman]

Many thanks for the explanation :-)

On 01/27/2014 01:13 PM, krad wrote:
> Neither of these setups is ideal, The best practice for your vdev is 
> to use 2^n + your parity drives
> This means in your case with raidz3 you would do something
>
> 2 + 3
> 4 + 3
> 8 + 3
>
> the 1st two are far from ideal as the ratios are low 8 + 3, so 11 
> drives per raidz3 vdev would be optimal. This would fit nicely with 
> your 26 drive enclosure as you would use 2x11 drive raidz3 vdevs, 2 
> hot spares, and two devices left for l2arc/zil. Probably best chop up 
> the ssds, mirror the zil and stripe the l2arc, assuming you dont want 
> to do down the route using generic SSD's rather than write/read 
> optimized ones

Yep was going to use your suggestion for l2arc/zil on 2x 128GB Corsair 
Force Series GS, 2.5" which have quite good w/r speeds - also I use 
these on other servers which tend to be quite good and reliable.

I think the way to create a mirrored zil and stiped l2arc would be to 
use GPT to partition the drives, then use the zfs features across the 
partitions.


Hmm.... so it also looks like I'm gona have to wait a while for some 
more drives then in order to create an 11 disk raidz3 pool.


But at least things will be done properly and in a good manner rather 
then going down a patch with "no return".


>
>
Regards,


Kaya