On Production SQL Server, we have following config:
3 Dell PowerEdge R630 servers, combined into Availability Group All 3 are connected to single Dell SAN storage unit which is a RAID array
From time to time, on PRIMARY we are seeing messages similar to below:
SQL Server has encountered 11 occurrence(s) of I/O requests taking longer than 15 seconds to complete on file [F:\Data\MyDatabase.mdf] in database id 8. The OS file handle is 0x0000000000001FBC. The offset of the latest long I/O is: 0x000004295d0000. The duration of the long I/O is: 37397 ms.
We are novice in performance troubleshooting
What are the most common ways or best practices in troubleshooting this particular issue related to storage ? What performance counters, tools, monitors, apps, etc. must be used to narrow down to the root cause of such messages ? Might be there is a Extended Events that can help, or some kind of audit / logging ?