is there any point of moving tempdb files into different disk drive if all LUNs are from the same RAID pool?

Question

According to best practices, it is recommended to move all tempdb (not just tempdb) files into different physical disk.

I have a virtual server which had originally 4 LUNs from the same RAID 10 pool. By the help of volume manager, I converted those 4 LUNs into 4 different volumes.

Now the question is, will it make any difference by moving tempdb into separate volume, or it is just fine to keep them with other SQL Server files in terms of performance?

Answer 1

There are several potential benefits.

1. Constraining TempDb Growth
2. Making disk-level performance counters more informative.
3. Separating the IO Queues so a log write IO never waits behind TempDB IOs in Windows.
4. Simplifying storage reconfiguration both in Windows and on the SAN.
5. Scaling across SAN controllers and enabling per-lun SAN optimizations.

Answer 2

Tempdb can grow immense if, for some reason, a nasty query. Is executed that eats up tempdb. Putting tempdb on a separate drive, which is the same storage under the cover, makes sure that your data or log volume won’t get full. If the tempdb volume gets full, you will receive an error message that tempdb is full, instead of your db possibly stopping because the data or log volume is full.