performance advantage by spreading 3 disk raidz1 across controllers?
Posted: 28 Apr 2016 18:17
I have a 3 disk raidz1 in a box that I created in the last couple of months. The mobo had 4 sata connectors. I wanted 3 more disks. So I bought a 2 port sata controller. It works fine.
Currently the config is
pool 1 (3 disks)
2 disks on 1st controller, 1 disk on the 2nd controller
pool 2 (3 disks)
1 disk on 2nd controller, 2 disks on 3rd controller.
So I have 3 separate controllers, 2 ports each.
Both pools are all currently running and have data on them
My question is, would there be any performance gain by changing the config so each pool has one drive on each controller? If there is a gain, is it worth messing with the configuration? If the expectation of performance gain is not much, I'd rather not bother.
For the most part this is serving multimedia files for playing and the performance far outstrips the requirement for playing back video. But occasionally I'm doing something in the background, like moving files from one set of disks to another, but not over the network. So I hardly need a major boost in performance, but it is always nice to have.
Current read speeds on both pools are about 80-85MB/s over the net. One pool is 1/2 full, the other is 3/4 full. With one pool (2 disks on 1 controller, 1 disk on the other) and close to empty, read speed was 95+MB/s. So I can't get much more over the network anyway, but I could get some.
Just did a dd to see speeds
(132 517 806 bytes/sec) on one
(181 800 196 bytes/sec) on the other
To me, this is pretty good. To you guys it might seem really slow
Currently the config is
pool 1 (3 disks)
2 disks on 1st controller, 1 disk on the 2nd controller
pool 2 (3 disks)
1 disk on 2nd controller, 2 disks on 3rd controller.
So I have 3 separate controllers, 2 ports each.
Both pools are all currently running and have data on them
My question is, would there be any performance gain by changing the config so each pool has one drive on each controller? If there is a gain, is it worth messing with the configuration? If the expectation of performance gain is not much, I'd rather not bother.
For the most part this is serving multimedia files for playing and the performance far outstrips the requirement for playing back video. But occasionally I'm doing something in the background, like moving files from one set of disks to another, but not over the network. So I hardly need a major boost in performance, but it is always nice to have.
Current read speeds on both pools are about 80-85MB/s over the net. One pool is 1/2 full, the other is 3/4 full. With one pool (2 disks on 1 controller, 1 disk on the other) and close to empty, read speed was 95+MB/s. So I can't get much more over the network anyway, but I could get some.
Just did a dd to see speeds
(132 517 806 bytes/sec) on one
(181 800 196 bytes/sec) on the other
To me, this is pretty good. To you guys it might seem really slow