Exchange 2007 memory

iaind · 11 Mar 2009 at 13:23

I recently installed a new Exchange 07 server and migrated our 25gb of mailboxes onto it from the old Exchange 03 box. Its running on 2003 x64 R2 on a DL380G4, 3.0Ghz Xeon and 3gb RAM. There's nothing else on it other than Sophos Puremessage and DoubleTake

I know Exchange is meant to use as much RAM as possible to optimise IO, but every few days, the store.exe process uses almost all the available memory and the server grinds to a halt. When it happens we regularly get "Outlook is trying to retrieve data..." messages and long delays in Outlook generally. Normally performance is superb and a restart of the IS process fixes it.

Never seen anything like this in 03, I know its not a huge amount of RAM but it should be enough, surely?

Has anyone else seen problems like this? Would limiting the memory usage to, say, 2gb solve the problem?

iaind · 11 Mar 2009 at 13:30

I did want to put more in it but its all I had spare (6 x 512), and its only a stopgap measure until our new ESX servers arrive.
About 90 users, fairly light usage. The old 03 box was fine with the same usage on a DL380 G3 (2.4Ghz) with 2gb RAM.

iaind · 11 Mar 2009 at 13:37

Thought that might be the case - its frustrating as while I understand it's a different beast to Exchange 03, the box isnt actually being used for anything more than the old one.
Will just schedule a nightly restart of the IS service in the mean time and give the virtual box 8gb when I build it

iaind · 11 Mar 2009 at 13:43

Seaniboy said:
This is the nature of exchange 2007, it will just comsume pretty much as much memory you can throw at it for caching. Strange that your getting "Outlook is trying to retrieve data..."

How many client's do you have? Is this box dedicated to exchange?

Thats what I expected, which is why I was suprised when it started grinding to a halt when it got to a certain usage. It's also strange that it performs flawlessly until this happens.

I may be wrong and the problem might be elsewhere, but normally when I look there's less than 50mb free RAM and restarting the store gets it going again.

It is dedicated to exchange with just the AV and replication software installed alongside. There's about 90 mailboxes but its rare for everyone to be using it at once - for example at this moment we have 52 active users

iaind · 11 Mar 2009 at 14:04

Seaniboy said:
Worth a look - http://technet.microsoft.com/en-us/library/bb738124.aspx

Which AV are u you using? Also what disk configuration have you setup?

Your mailbox and usage count is similar to mine, we have 4GB in a dual quad core machine and it is consuming about 95+% of the physical memory but clients do not have any problems. Trying to use the box from the console/rdp can be quite painful though.

2 x 36gb 15k mirror for OS and logs, 4 x 36gb 10k RAID5 for the data. Again, not optimal but we're not hitting any bottlenecks with it.

AV is Sophos Puremessage, which isnt great to be honest.

One thing I did notice was someone (not me!) had set the pagefile to 2gb fixed, so I changed it to system managed and will schedule a reboot tonight.

I did think if the server was underspecced we'd get consistent sluggish performance, but this flies 99% of the time and just seems to hit a wall

iaind · 11 Mar 2009 at 14:15

I would be suprised if that doesnt help at least, not sure which numpty set it like that!

iaind · 12 Mar 2009 at 07:46

Yep definitely, when you install sophos puremessage for store scanning, it also installs the regular AV and excludes all the correct paths.
I'm not excluding Sophos generally being crap as the source of the problem, though, as it wouldnt be the first time. It caused our file server to lock up for a minute every time someone saved an encrypted file....

iaind · 15 Mar 2009 at 01:49

?? Ok...

That's because the minimum requirement for SBS 08 is 4gb and is probably enforced during setup. The minimum for Exchange 07 is 2gb.

iaind · 19 Apr 2009 at 11:19

A quick update, incase anyone actually cares.

Sorting out that PF seemed to sort the problem out. The server has now been migrated to a Windows 2008 VM with 6Gb RAM assigned to it and its performing perfectly

It even vMotions fine without any client interruption or delay whatsoever

iaind · 19 Apr 2009 at 11:31

Incidentally - does anyone have a good guide for decomissioning an unused 2007 server? Have set the send and recieve connectors (and bridgehead for RG to 2003 server) to the new box and will set a DNS alias after decomissioning for client access, but is there anything else I need to do?