memory usage server.exe

guydeschepper@hotmail.com

Hello Navision Friends,

We have an issue at a customer site which is driving us (and them) crazy.
Their Navision installation is too slow, although the environment should be more than performant enough.

they have a HP G6 server, with ESX on it installed. 2 virtual servers (a file server and a navision server) are configured, each with 2Gb of RAM. Navision native server 2009SP1 is installed, with 800Mb cache, commit cache has been set to True. the database itself is 21Gb. It has been running smoothly for months, but since a couple of weeks the performance has dropped seriously.

When monitoring the server, we see that the disks regularly are heavily stressed (perfmon shows Avg disk queue length topping to the max for a long time), but what is more odd to me is that the memory usage shown in the task manager is quite different from what we expect.
In normal situations, when 800Mb were assigned of a server with 2Gb or RAM, the task manager would show a memory usage of approximately 800mb with More than 1Gb of free memory. In this case, the memory usage is continuously swapping and is max. 500Mb with only 50MB of free memory. No other processes in the taskmanager could explain the huge "loss" of memory.

Is there anybody who could point me to a solution ?
Tons of thanks upfront !

Sog

since the disks are heavily used and the memory is full, I'd say that the server itself (not the virtual server) is using up the memory. See if the memory is assigned correctly to both virtual servers, that the server itself has at least 6 GB of memory 2 x 2GB for the virtual servers and the server itself 2 GB.
Other than that, it can be a number of things, services using up a lot of memory, the server running the virtual servers could be the cause, disk "sharing", ...

Maybe shut down the NAV server service, and see where the memory goes.

kriki

Some possible things I think about:

Something is running on your NAV VM that is leaking memory. You can check that by doing a reset your your NAV VM. If all works fine for some time, it probably is this. What program? Probably something that has been installed a couple of weeks ago (or a Windows update that goes wrong).

Another possibility: with VMWare it is possible to give more memory to all the virtual machines than there is physical memory.
E.g. you have 8GB of physical memory and you have 3 VM with each 4 GB of memory for a total of 12GB virtual memory. This means that VMWare has to swap memory (if the VM's together use more than 8GB of memory) of the VM to disk and if the VM needs it again, VMWare has to put it back. I don't think the VM should see this with the normal performance counters. To check this: ESX has a dashboard where you can see what is happening to the physical machine and the VM's.

guydeschepper@hotmail.com

Hello,

thanks for the replies so far.
I know a little of the memory optimalisation by VMWare. But the VM's have each 2Gb dedicated memory according to our infrastructure guy. And he does not found any problem of memory leakage on the VMWare level itself.

I thought of software installations too, but didn't try to uninstall some of the latest windows updates yet to see whether these are causing the problems. I will try that next week. Last night I reïnstalled the Navision service, I have no idea yet if this could solve the problem.

I'll keep you posted, but if anyone else has some ideas in the meantime ...