We have many instances of SQL Server 2008 Workgroup Edition that ran great on SQL Server 2008 SP1 however after these nodes have been upgraded to SQL Server 2008 SP2 or SP3 we have had an issue where we are seeing large quantity of 833 warnings only when doing a Transaction Log Backup. I've tried moving the Transaction Log backups to other drives but the IO warnings always occurs on the primary MDF file. This is setup with transction log files being stored on a RAID 1 volume and the database files stored on a RAID 5 volume. I understand it is better to use RAID 10 but I don't have that option here and this has been running great for a couple of years before the Service Pack updates. The interval of the log backups is every 15 minutes.
SQL Server has encountered %d occurrence(s) of I/O requests taking longer than 15 seconds to complete on file [%ls] in database [%ls] (%d). The OS file handle is 0x%p. The offset of the latest long I/O is: %#016I64x.
If I stop the Transaction Log backups the warnings completely go away.
David Ryan