We use Equalogic SANs. The SANs contains both SAS and SATA disks. The SAN has an automatically balancing feature so servers with a lot of disk activity will be routed to the SAS disks. This is done on block level.
I have a few servers with a lot of daytime-load that I do not want to reside on the fast disks, as they are not mission critical for me. I could create a datastore that is dedicated to SATA disks, but that will leave me with hard limits for sizes and future expanding.
I wonder if I can limit the resource usage instead? If a drive get a Disk resource allocation of e.g. 50 iOPS, will the activity be decreased and be less heavy on the faster disks?