Multiple volumes vs single volumes for SQL Server CHECKDB performance We have a ~10TB database with dozens of data files on SQL Server 2017 Enterprise CU21. We're seeing slower CHECKDB performance when all of the files are on a single volume as opposed to multiple volumes. (In both cases, the same high-end (Pure) storage is involved, same VM hosts, same storage network - just different numbers of volumes.)
Is there a documented advantage to spreading data files across multiple volumes, either for DBCC CHECKDB specifically, or for SQL Server generally?
The trace flag 2549 described in KB 2634571 tells CHECKDB to treat each database file as if it's on a unique drive. But is there any other official documentation outlining how SQL Server (or CHECKDB specifically) treats IO differently when there are multiple volumes involved?
Is this what you're looking for?
https://techcommunity.microsoft.com/t5/sql-server-support/a-faster-checkdb-8211-part-ii/ba-p/316882
At the end of this blog Bob Ward says:
There are also some factors that can affect whether these changes actually help make your execution of CHECKDB faster:
...
Spreading files across disks – As with the general performance of server queries, if we are spreading out our reads across separate physical disks for files, we can achieve better I/O performance.