When setting MAX_IOPS_PER_VOLUME in a Resource Pool, what exactly does "volume" mean? Specifically, how many "volumes" would be the following cases:
- Locally attached disk that's split into two partitions E: and F:
- Software RAID 1 set E: composed of 2 locally attached disks (yes I know software RAID is bad-- adding this case to help me understand SQL Server's definition of "volume", not to design a production setup!)
- Hardware RAID 1 set E: composed of 2 locally-attached disks
- SAN disk E: on who knows/who cares how many disks.
- 1 SQL Server filegroup spread across two locally attached disks E: and F:
I assume the answers to #3 and #4 are "1 volume" and #5 is "2 volumes" but it's #1 and #2 that I'm most curious about.
The specific reason I'm asking is wondering if it's possible to increase the Resource Governor's IOPS limit for locally-attached SSD tempdb while having a lower limit for our SAN data storage.
So I'm wondering if splitting a single physical disk into multiple partitions might be a way to do this, by putting separate tempdb files on each partition so the total tempdb If #1 above makes SQL Server treat one physical disks as multiple volumes for throttling purposes, this may be an option. I'm assuming that this won't work-- that SQL Server is smart enough to know that 2 partitions is one "volume". But was worth asking.