Unity paging high but still lots of memory left

[d.anthony.hadley_2]

I have several Unity servers (all win2k, sp4) with varying versions of Unity. They are all paging high, 70-98% even though there is enough physical memory left. e.g. one Unity server,4.2 Build 4.2(1) Win2K sp4, has 3 gigs of memory, it is paging 98% but there is still almost a gig left of physical memory. This just doesn't seem normal. Is there a way to see what is using the page file? what can I do about this? Thanks.

[Ginger Dillon]

Hi -

Here is a good Microsoft reference for paging/memory problems - http://www.microsoft.com/technet/prodtechnol/Windows2000Pro/reskit/part6/proch28.mspx?mfr=true

Two questions I have are:

1. How many page files do you have per Unity server? If only one on your OS partition, which may also be running Unity, you may want to consider adding a page file to a different physical drive that is not part of the same logical drive. If you have a RAID-5 set, you can put it there for better performance.

2. Does the problem disappear if you reboot the server? If yes, you may be experiencing a memory leak. If suspected, I would consult TAC.

Ginger

[d.anthony.hadley_2]

Thanks for the response. I have one page file on the OS partition. I have mirrored drives only, no RAID 5. The problem clears when I reboot but slowly comes back. It did this also when I only had 1 gig of mem. I added the memory to alleviate this problem, thinking that it was not enough memory, but it continued after adding two more gigs. SQL is taking about 1.2 gigs of memory but McShield.exe has the highest number of page faults.

Thanks for the doc. I'll go through it and set up some monitoring.

[Ginger Dillon]

Hi -

The symptom you described as "The problem clears when I reboot but slowly comes back." can very well be indicative of a memory leak. You mentioned Unity 4.2 for one server, but not the other versions. Unity 4.0(4) and (5) had some bugs related to memory. You could check in BugTool for these to be sure, but I would also consider calling TAC on this. Just a thought on McShield.exe - it is the McAfee On-Access Antivirus Scanner. Have you excluded the C:\Commserver directory from scanning? That is the recommendation.

Ginger

[Tim Lowrey]

Hi Anthony, I have a similiar problem. I think I can create it by running DbWalker. Have you ever run DbWalker? SQL memory and Pagefile go through the roof after running DbWalker and do not come back down. I don't see any immediate affects to functionality, but it's driving my monitoring team crazy.

I'd be interested if you see problem after running DbWalker and also interested in how many subscribers you have total (All subscribers in network if you use digital networking). I'm running 16,000+. Tim

[d.anthony.hadley_2]

Hi Tim, I haven't checked memory usage after running DBWalker. I've been dealing with the memory issue for 5 years for both CallManager and Unity: high memory usage, no performance degredation, constant monitoring alarms. Basically, there is no Cisco paper on memory utilization, that I have been able to find. I had opened several TAC cases and only verbally got information on memory for CallManager, Unity is similiar, I believe.

They will take all available memory and apportion it to the services as they need it. I have seen where more physical memory is added, then it is taken by the app. Normal convention would say that the server is going to crash. But, I haven't seen one crash in 5 years due to memory. Several Unity servers went almost 2 weeks with the paging file at 100%; the customer had no performance problems. Now, I ignore all memory alarms.

There are minimum memory requirements for hardware and number of devices and apps unning. You'll have to search the CCO, I don't have the links handy. I hope this helps.

[Tim Lowrey]

Thanks Anthony, same experience here... High memory usage, but everything seems to working normally. I just opened a TAC case and basically they say it's (Microsoft SQL) is working as designed (provided references to Microsoft). Likewise on the page file usage. It's allocated 98-100% but that does not mean it's paging all the time. Maybe at one time, but not all the time. We just don't see this type of behavior on our other 1000+ Windows servers, so it's just a little un-nerving. Thanks again.