Very High Current Disk Queue Spikes
Posted on 2007-11-26
We have a Managed SQL server 2000 cluster running against a SAN disk set. At occasional peroids we seem to suffer a very high number of SQL Deadlocks and performance issues. I decided to monitor the SQL server and during this peroid I was monitiring Avg Disk Queue Length, Current disk queue length., Disk bytes/sec, SQL transactions/sec and a few others. Now normally the Disk Q sits around .05 to.5 but at certain times I noticed the the current queue length would climb to around 850+ over 25 seconds with no significant increase in bytes/sec or trans/sec. Could this be a SAN config issue? What areas can I investigate considering this is a Managed server and only have restrcited remote access to the server. I can provide a screenshot of the spike. The support company say the stats are irrelvant and the issue is with the application and they can't see anything with the system.