Drives flow down hill= Making 4Kn & 512E play nicer in the same pool

[AVB]

New drives for the main server mean the 2nd server gets the old, larger different drives. This time I am also changing the pool from 2 Zvols of 9 dives each in the pool to 2 Zvols of 8 drives each and adding a new pool with 8 drives.. So, pool #1 Zvol #1 will have 8 SAS 4kn drives and Zvol #2 will be 8 512E Sata drives. Pool #2 will be doing its own thing with 8 sata drives. Is there anything I need to do to make the 4Kn and 512E drives play nicer in Pool #1? I know they will work together even on the same HBA (Dell Perc H310) but since I'm doing a clean slate I thought I'd try ot optimize what I have until the next drive upgrade. Thanks!

 

[artlessknave]

you need ashift=12 iirc. i think it's the new default.
ashift=9 works poorly with any 4kn. used to be default.
i have 4kn and 512e mixed, no problems observed.

 

[AVB]

you need ashift=12 iirc. i think it's the new default.
ashift=9 works poorly with any 4kn. used to be default.
i have 4kn and 512e mixed, no problems observed.

Doesn't ashift work globally on all drives? If not, how do you delineate which drives are to be shifted?

 

[AVB]

you need ashift=12 iirc. i think it's the new default.
ashift=9 works poorly with any 4kn. used to be default.
i have 4kn and 512e mixed, no problems observed.

I dug around and found a command to check ashift on my pools and it is already set at 12. Thanks for pointing me in the right direction.

 

[artlessknave]

If not, how do you delineate which drives are to be shifted?

easy. it's not set per drive. if you are making a new pool, make it 12. 12 works fine with 4kn, 9 doesn't.
afaik, the reasons to make a pool 9, if any, are generally inferior to being able to just use 4kn and 512e drives at the same time.
sounds like you are all set, so yay!