Explanation: This is a general indicator of performance problems. High stall times indicate I/O problems, which can be attributed to busy physical disks or queries that return large data sets to the client.
Guideline values: The ideal value for this metric should be less than 100, but this is just a rule-of-thumb. Higher values may be acceptable for your organization.
- Disk avg. read time
- Disk avg. write time
- Avg. disk queue length
IO Stalls are affected by three possible factors:
- poorly performing disk subsystem (such as a misconfigured SAN)
- poorly defined queries
- overloaded disks (“data bursts”)
Solutions may involve allocating new hardware resources in addition to performance tuning of individual queries.
More information:Average I/O stalls,