Terminal Server oriented ESX 3.5 servers

[Box293]

If you're into virtualizing Windows Terminal Servers then you will have discovered that their performance isn't that crash hot.

To help with this in the past we made the following configuration changes to our ESX servers:

• Click on Inventory button along the top

• Expand Hosts & Clusters select the ESX server

• In the right pane click the Configuration tab

• Click the Advanced Settings link

• Click Mem (left hand side)

• Mem.AllocHighThreshold = 4096 (default 1500)

• Mem.ShareScanTotal = 0 (default 200)

• Mem.ShareScanVM = 0 (default 50)

• Click the Summary tab in the right pane

• Under Commands click Reboot

• Click Yes and then type the reason Changed Terminal Server Memory Settings and click OK

• Wait for the server to reboot

Anyways getting to the point, since we upgraded to ESX 3.5.0 we have noticed two of the settings are now missing:

Mem.ShareScanTotal

Mem.ShareScanVM

So does anyone know why they are missing?

.... Oh and also does anyone have a magic solution to improved virtual terminal server performance ;o)

[chrisy · Accepted solution]

The ShareScan settings have turned into Mem.ShareScanGHZ, Mem.ShareScanTime, Mem.ShareRateMax. The defaults seem to scan more aggressively than the old defaults; I used to set general-purpose servers to scan more but now don't bother.

Setting ShareScanGHZ and ShareRateMax to 0 should disable page sharing on the server. Also, PAE is apparently not such an issue with ESX3.5, so although I've not tested it there may not be such a need to disable it anymore by the altering of AllocHighThreshold.

--

Chris

[Box293]

Thanks very much for that.

Where did you find out this information from? I have a co-worker that doesn't trust forums and would like some hard evidence about when to use these settings and why.

Cheers

Troy

[admin]

Hi,

Chris is right. I've done some reading and made a comparison. Mem.ShreScanTotal and Mem.ShareScanVM is now Mem.ShareScanTime and Mem.ShareScanGHz. Though it's not documented about the changes, but the definition explicitly identify the same terminology. See "Resource Management Guide" Page 150 & 151.

Mem.ShareTime and Mem.ShareGHz is defined as an advanced settings to control the rate at which the systems scans memory to identify opportunities for sharing memory.

Mem.ShareScanTotal specifies the total systemwide rate at which memory should be scanned for transparent page sharing opportunities. This is very similar to Mem.ShareScanVM which is also the rate at which the system scans memory to identify opportunities for sharing memory.