RAM Consumption at 60% at idle

[jcrapps]

Hello,

I have an Exchange Server (2007 SP1) that's hovering around 60% RAM usage at idle. This server is pre-production and I just want to make sure that it will be okay before we go live. I ran a stress test for 10 hours and no problems during that test. I kind of need this answer quick so I don't have long to scour the internet.

Thanks!

 

[xmsre]

store uses RAM (a lot of it) to cache database pages. This is normal.

 

[ShackDaddy]

This is the one of the main reasons why Exchange and SQL servers are supposed to be dedicated. Both preallocate a large chunk of RAM. E2007 is optimized (hello 64-bit!) to utilize ram even more heavily (or perhaps just efficiently) than previous versions of Exchange were.

Dave Shackelford
Shackelford Consulting

 

[jcrapps]

Man, this is only an exchange server but I'm starting to read about how store.exe is a RAM hog. I've read about people losing all their pagefile and ram to cache information for Exchange. I know that MS is touting this as a new feature, but I hear that it's also causing a lot of problems. from the eyes of an untrained technician, it can appear to be a memory leak. Here's a couple interesting articles on this that I found:

http://msexchangeteam.com/archive/2004/08/02/206012.aspx

http://forums.microsoft.com/technet...3&siteid=17&sb=0&d=1&at=7&ft=11&tf=0&pageid=0

 

[58sniper]

Store.exe isn't a RAM hog.

It's not a problem for a properly sized and configured server. And anyone who doesn't read the documentation and understand how the application utilizes resources shouldn't be using it. It really is that simple. I'm not pointing fingers. But we see all too many people complaining about memory leaks or server problems when a little bit of reading and/or searching would uncover the theory.

The more memory, the better it runs. Nothing new there. It's been that way for years. The more store.exe can run from RAM, the less it has to work from drives. Simple performance guidelines. That's one of the reasons why you never virtualize any version of Exchange.

Pat Richard
Microsoft Exchange MVP
Contributing author Microsoft Exchange Server 2007: The Complete Reference

 

[Zelandakh]

Never virtualise Exchange? Oops

 

[xmsre]

The more you cache, the less IO actually hit the disk. This means you can use bigger and slower and presumably cheaper disks. Case in point: Exchange 2007 generates 70% less disk IO than Exchange 2003. Thre price you pay for the reduction in disk IO is RAM utilization.

When you start taking RAM away or trimming the working set, especially during cold start, ugly things can happen. One I've run into a few times now is

http://blogs.technet.com/mikelag/archive/2007/12/19/working-set-trimming.aspx.

Applying the hotfix 938486 did help a lot, but you still see the IO spike when trimming starts.

 

[Zelandakh]

In other words, lots of RAM in use when you think nothing is going on means better performance from Exchange.