% Disk Time counter

I'm monitoring our database server and the "% Disk Time" counter in the
"Physical Disk" object is confusing me. Over a 24 hour period I'm getting
Min = 0.15, Max = 20269 and Average = 136. I am monitoring the database
drive itself not transaction logs and the database is on a RAID 10 SAN. Can
anybody shed any light on how I should read these figures?
thanks
Gav% Disk Time is more or less meaningless. It's just (average disk queue
length) * 100. Better to monitor the queue length itself, and correlate
that number with counters like Avg Seconds/Read and Avg Seconds/Write. A
queue of 202 may indicate a problem, but you really need those average
counters to find out how bad things are really getting.
Adam Machanic
SQL Server MVP - http://sqlblog.com
Author, "Expert SQL Server 2005 Development"
http://www.apress.com/book/bookDisplay.html?bID=10220
"Gav" <gav@.nospam.com> wrote in message
news:uTHfuPy8HHA.1164@.TK2MSFTNGP02.phx.gbl...
> I'm monitoring our database server and the "% Disk Time" counter in the
> "Physical Disk" object is confusing me. Over a 24 hour period I'm getting
> Min = 0.15, Max = 20269 and Average = 136. I am monitoring the database
> drive itself not transaction logs and the database is on a RAID 10 SAN.
> Can anybody shed any light on how I should read these figures?
> thanks
> Gav
>|||Also:
For calculation, you need to divide the test result to your physical disks'
count. (If you selected "Total_" object instead of a specific disk.)
For example there could be 8 disks on your SAN then you need to divide the
result to 8 to find the correct analysis.
--
Ekrem Önsoy
"Gav" <gav@.nospam.com> wrote in message
news:uTHfuPy8HHA.1164@.TK2MSFTNGP02.phx.gbl...
> I'm monitoring our database server and the "% Disk Time" counter in the
> "Physical Disk" object is confusing me. Over a 24 hour period I'm getting
> Min = 0.15, Max = 20269 and Average = 136. I am monitoring the database
> drive itself not transaction logs and the database is on a RAID 10 SAN.
> Can anybody shed any light on how I should read these figures?
> thanks
> Gav
>