Terminal Services - Way too much Disk writing

[kyle83]

I was trying to determine how much data was being written to my servers' hard disks today and I downloaded a program called SSDReady which shows me how many MBs are actively being written and read from the disk.

First I tested it on my SQL2005 server, and its only needs to write about 500MB every 2 hours, which is great...

However, on the Terminal server, There are 2 GBs being written to disk in only 30 minutes.. The server has 4 gigs of ram, and 6 gigs for a page file. Task manager reveals that there is always around 2 gigs of physical memory free so I can't for the life of me understand why the system is paging so much data. Looking at the performance monitor built into server 2003, it shows me that the system is paging a ton of data when users are active in the RDP session. For example, if a client opens a new window in the program they are using it writes another 10-20 megabytes to disk. When they close that window, it seems to do something similar. We only have 8 active users on the TS, and a ton of free ram (2 gigs).

At this rate the system will be writing almost 50 gigs a day to disk.. The more active the users are the more it writes to disk. The program they use, doesn't need to write much of anything to disk as all data it is accessing is on the SQL server.

I tried installing the hotfix KB956438, based on information I got elsewhere, but that didn't help this issue.

Can anyone point me in the right direction?

Thanks

 

[ShackDaddy]

Does your SSDReady app show you which programs or which locations are writing to disk? It's possible that the SQL Server is merely committing writes to disk and the rest are retrieval reads to provide data to the client, and the indexes/views for those retrievals are mainly being pulled from RAM. Is your SQL server 64-bit? That would also help explain things, since it's probably been optimized for RAM usage.

On the TServer, on the other hand, those same queries may be cached as non-critical data that the system finds the page file to be the most useful place to store them. Plus, since the TServer doesn't probably keep much persistent data per-user in the profile, any logon may be having to cache the SQL data from scratch, so the same data may be re-written each time a user logs on.

Finally, have you looked at this document?

http://winadminnotes.wordpress.com/...minal-services-server-for-better-performance/

One thing the article mentions is that having a page file of larger than 4gb isn't possible on a 32-bit system. I'm not sure that that's true, but it made me wonder whether your Win2003 TS is a 64 or 32-bit box.

Dave Shackelford
ThirdTier.net
TrainSignal.com