HDD Speed on KVM and Host (Node)

[informant]

fine, on our dl785 we use a p812 controller with 1 gb ssd-cache and on this is a msa storage with 12x 3tb wd hdds on raid 6. this is a better controller, i think, or.

regards

 

[sumsum]

yes, this must be a better controller

 

[informant]

what for a controller do you use or recommend?
regards

 

[sumsum]

well ,this is depending on the use case. anything better than a P400. as you can see in my tests with a P420i. Use SAS 15k Disks or SSD Disks - may be another good option to improve the situation you are facing.

Edit : another point of improvement may be : use virtio for HDD, use RAW format instead of qcow2 if you realy need speed.

 

[informant]

ok, but wy is the speed very different of node and kvm?

ok, raw we can test, well virtio we use everytime.

 

[sumsum]

I dont know , I'm Sorry. Maybe we have some more advanced users here in the community to answer this questions. If you search the web you might find different answers.

 

[informant]

ok, no problem, very thanks for your help and have a nice day.

best regads

 

[spirit]

use raw format, virtio disk, cache=none. check that partitions are correctly aligned.

They are no reason you couldn't reach same speed than host.

(virtio disk can goes up to around 100.000 iops)