Citrix PS 4.0/4.5 Physical Memory issue(make use of 8GB ram)!, in the Performance Tuning / Server Sizing forum on BrianMadden.com

Hi all,

Recently, one of our customers face the Memory issue in Citrix session:-

Basically, the Citrix environment for the customer is:

1. Single AD domain;
2. one Citrix PS 4.0(Windows Server 2000 Member server);
3. The Citrix Server hardware config.(8GB Physical Memory);
4. A customized Oracle Application installed and published on the Citrix Server;
5. 12 users will concurrently make a ICA session with the Citrix server that launching the Oracle application.

The sympthom is that when one user make a ICA session to the Citrix server that using that Oracle application, the Memory will occupy 500-600mb memory (i.e. 12 users * 600mb = 7200mb memory).

But the Windows 2000 OS and Citrix PS 4.0 can only use 4GB of Physical memory!!! And at that moment, the system will perform very slowly if all the 12 users launchs the Oracle application concurrently.

*** If the customer try to use the following Windows OS and Citrix PS combination, which configuration will make use all of the 8GB of Physical memory of that Citrix Server?!

1. Windows Server 2003 Enterprise (X86)(supported up to 32GB Ram) + Citrix PS 4.0
2. Windows Server 2003 Enterprise (X86)(supported up to 32GB Ram) + Citrix PS 4.5
3. Windows Server 2003 (X64) + Citrix PS 4.0 (x64 Edition)
4. Windows Server 2003 (X64) + Citrix PS 4.5 (x64 Edition)

In addition, are there any supported Official documents from the Citrix that provide the related information for the MEMORY limitation for the Citrix PS 4.0 / PS 4.5 ?!

Thanks for your help!!!

Regards,
Song

x64 versions of windows 2003 (standard) will not require you any extra money if you're already running x86 windows 2003 (standard).

x64 does let you use more than 4 GB of memory. The problem is running 32 bit applications on 64 bit windows. To run a 32 bit app, it requires 1.8x the amount of memory it normally takes to run that app on a 32 bit windows server.

So, if memory is your bottleneck you should go to x86 enterprise windows 2003 and just add more than 4gb of ram.

The limit of all the 32 bit versions is that the system can address no more than 2 Gb of RAM. Using for example Windows 2003 enterprise edition or maybe even datacenter edition will allow you're users to address more memory than the 4 Gb limit in windows 2003 standard, however, you're still limited to the 2 Gb system memory space.

64 bit windows does not have this limitation, however the 64 bit architecture does come at the cost of added overhead when it comes to memory addressing.
Like jody states, 64 bit architecture only works correctly when all components can run in 64 bit mode. This you really need to check. If you, for any reason cannot run your setup in a 64 bit architecture you could consider running windows 2003 enterprise edition with the /PAE switch in boot.ini.

--Cheers--
Siegfried Huijgen

If the user is still using32bit Win2k3 Std, you can always use the /3Gb switch to bump the address space to 3 Gb. And remember that this is the memory address space per application, so multipe users should in theory be able to occupy more space.

 

 

to the OP

 

I went through some similar issues earlier this year. Go with win2k3 Enterprise. The version of Citrix is less important. I went with 4.5 because it was the latest at the time. I can easily push memory into the 5-6 Gb range now before other factors slow down the machine.

OR

Just get 2 smaller boxes with win2k3 std and split the users. This is obivously less efficient and a bit more work, but you add farm level redundancy.

Hi Song,

You can try the /PAE switch http://www.microsoft.com/whdc/system/platform/server/PAE/PAEdrv.mspx it's been around a long time (since Pentium Pro) but on a W2K server, your practical limitation is 4GB.

"3. The Citrix Server hardware config.(8GB Physical Memory);" Doesn't tell us much about the physical server, but I'll extrapolate that it's getting "long in the tooth" as it's still running W2K. Which BTW, has passed EOS and should have been upgraded to W2K3 a couple/three years ago. IMO - Folks that are currently running W2K3 should be 6 months or more into proof-of-concept to W2K8! http://support.microsoft.com/lifecycle/?p1=7274 So, I would take a look at the other server physical attributes before deciding whether to just upgrade the OS, or perform a bare metal upgrade. Performance logs should tell you if it's up to snuff. With just 12 users, W2K3 Ent w/8GB RAM and a 2-4GB page file should probably do the trick.

Correct me if I'm wrong, but is it possible they have the actual Oracle database installed on their Citrix server (not a good practice)? I would recommend you install the Oracle database on a separate server, a SUN box (as Oracle would prefer). Make sure it's sized right and has at least a RAID1 config or some version of Mirrored Stripe http://en.wikipedia.org/wiki/RAID for performance. Install and publish the Oracle front-end application on your Citrix box and you'll realize a huge performance gain (and scalability).

Hope this helps,

 

Hi There,

I am going through same scenerio and want to invetigate further.

for one of client, who have around 90 citrix servers where around 300 apps published 4.5 and metaframe

window server 2003 enterprise with 8gb ram

it is observed sometime, that one application connected by a single user (iexplorer/excel.exe or winword etc) consumes more than 500MB Ram/ sometime upto 1.5gb, other users connected to the system using normal memory. so around 60 users found connected and working but reported very slow performance

All users face slow performance of application. This is surprising enough that how come apps like ie / word/ excel can eat up that much space.

This is very similar to problem reported by song. 

Ok, first and foremost, MOVE TO X64!

we had some serious performance issues with 32bit Server 2003 Enterprise. We moved to x64 of the same and POOF performance issues gone. We were using up the available kernel memory space long before we used up the userspace. 

Which BTW, enabling /PAE eats up more kernel memory compounding the problem.

Moving to X64 eliminates PAE.

Server 2003 Standard edition, regardless of X64 or X86, is limited to 4GB of RAM, so you'll need to go to enterprise.

Here's my recommended config:

Server 2003 Enterprise X64 with PS4.5/XA5, or if possible 2008R2 with XA6.  Put as much memory as possible in.  

 

Please keep in mind that your hardware MUST support 64bit, so if it's originally a 2000 box, it may not support X64.

Dan Hamik:

Server 2003 Standard edition, regardless of X64 or X86, is limited to 4GB of RAM, so you'll need to go to enterprise.

 

Not true. Server 2003 and 2008 Standard (R2) at x64 can use a maximum of 32 GB of physical memory. Enterprise is not necessary unless you need memory beyond 32 GB.