[THIN] Re: XenServer Slowdown

  • From: Dan Dill <DanD@xxxxxxxxxx>
  • To: "thin@xxxxxxxxxxxxx" <thin@xxxxxxxxxxxxx>
  • Date: Wed, 17 Nov 2010 14:44:49 -0800

While it's good to nail down the memory config it seems strange that the memory 
would affect the server coming to a crawl after a period of time....  That 
symptom more points to software I would think...

Dan Dill

From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of 
Berny Stapleton
Sent: Wednesday, November 17, 2010 2:21 PM
To: thin@xxxxxxxxxxxxx
Subject: [THIN] Re: XenServer Slowdown

Don't forget the toss up between UDIMM vs RDIMM.

UDIMM is faster than RDIMM but not registered, there is a memory limit on the 
amount of UDIMM you can run as well. Depending on the situation your in, this 
might be a trade off your willing to make.


On Wed, Nov 17, 2010 at 9:05 PM, Joe Shonk 
<joe.shonk@xxxxxxxxx<mailto:joe.shonk@xxxxxxxxx>> wrote:
32 gigs is the limit for Windows Server Standard 2008 x64.  Enterprise will do 
1 terabyte.

The one thing that jumps out at me is the number 36.  Generally with a 2 proc 
Nehalem based system you would expect to see memory in the following multiples: 
1, 12, 24, 48 or 96.  Yes there are other memory configurations that work but 
they generally indicate that the memory is not optimized.

The number 36 means to me that you're running either (6 x 4gb dimms + 6 x 2gb 
dimms) or (18 x 2gb dimms).  The later configuration would choke your memory 
bus speed from 1333MHz to 800 MHz.

I would also check to see what rank the dimms you have are.


From: thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx> 
[mailto:thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx>] On Behalf 
Of James Scanlon
Sent: Wednesday, November 17, 2010 9:46 AM

To: thin@xxxxxxxxxxxxx<mailto:thin@xxxxxxxxxxxxx>
Subject: [THIN] Re: XenServer Slowdown

XenApp - Correct
Windows 2008 SP2 - not R2,
Windows system reports 36GB in system properties, HP SIM reports 32GB of ram 
addressable / available - WTF? - chasing this up for further details.......

From: thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx> 
[mailto:thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx>] On Behalf 
Of Joe Shonk
Sent: 17 November 2010 16:28
To: thin@xxxxxxxxxxxxx<mailto:thin@xxxxxxxxxxxxx>
Subject: [THIN] Re: XenServer Slowdown
I'm going to out on a limb and assume that you are referring to XenApp and not 

First question, why Windows 2008 Standard x64?
                Windows 2008 R2 is going to be a much better choice, especially 
if you are running this directly on new hardware.
                Second, Standard edition only support 32 gigs and you're 
showing 36 gigs

Also, which metric is sitting at 25% utilized?


From: thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx> 
[mailto:thin-bounce@xxxxxxxxxxxxx<mailto:thin-bounce@xxxxxxxxxxxxx>] On Behalf 
Of James Scanlon
Sent: Wednesday, November 17, 2010 8:45 AM
To: thin@xxxxxxxxxxxxx<mailto:thin@xxxxxxxxxxxxx>
Subject: [THIN] Re: XenServer Slowdown

(sorry about last unfinished email went to save to get more info and clicked 
send - sigh)

We are having speed issues with our XenServers

 *   Brand New builds
 *   Deployed with Altiris
 *   Xenserver 5.0
 *   Windows 2008 Standard 64bit
 *   36GB RAM
 *   Dual CPU, 8 Core processors X5560 2.80Ghz
 *   Appsense EM and PM (with citrix CPU and memory management disabled)
 *   Sophos AV
 *   HP Hardware DL380 G6 with teamed nics
For normal operation we are getting 25 second login time (to desktop)

After approx 30 users (or 2 days without a reboot), the performance drops to 
1-1.5 minutes just to log in, everything sluggish, cant open task manager even 
though multiple taskman icons appear in systray.
No performance issues on the systems themselves, all sitting around %25 
utilised. (CPU, MEM, DISK etc)

So far:
We have disabled Sophos, no result
disabled Appsense, no result
turned on VT instructions for CPU in the BIOS, no result
turn off TCP offloading for the NICS
HW firmware for Servers / patching (latest PSP)
Software for OS and apps / patching

Any one seen anything like this already? apart now from bringing up a VM host 
to eliminate hardware or a full manual rebuild and testing at each stage of the 
build process - we are starting to run out of 'obvious ideas'
ANY assistance and advice greatly appreciated!



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