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Do I need more memory? RRS feed

  • Question

  • Here's my Exchange server specs:
    Window Server 2008 R2 Standard SP1 (64-bit)
    Exchange Server 2007 Standard SP3 + update rollup 3-v2
    Xeon 5110, 1.6GHz (2 CPUs)
    12GB RAM

    This is the one and only Exchange box. I don't use Edge Transport server. I have about 35 mailboxes. Some mailboxes are as large as 10GB. Mailbox Database is about 50GB. Physical memory usage is between 92% to 96%. Store.exe uses as much as 10GB RAM. This post is NOT about why store.exe uses so much RAM. I understand that it is normal behavior.

    My question is do I need more physical memory? Will it help if I add an extra 8GB so the total system RAM is 20GB? What do I have to check to see if adding RAM will indeed help to speed things up.

    Thanks.


    • Edited by morph2-7 Thursday, September 22, 2011 6:12 PM
    Thursday, September 22, 2011 6:07 PM

Answers

  • Exmon are just tools used by the Performance Tool. The fact that they are not enabled isn't an issue.

    My home server has two arrays, one for the OS/Logs and one for the database. And that has a grand total of five mailboxes and one user (me). I have clients with less users on dual arrays. You don't look really at the users at this level, but what they are doing with the data. 30 users with a 20gb store, not an issue. 20 users each with 20gb mailboxes, then you could benefit.

    If the performance troubleshooter didn't flag anything then I would simply forget about and leave it alone.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.
    • Marked as answer by morph2-7 Thursday, September 22, 2011 11:44 PM
    Thursday, September 22, 2011 11:36 PM

All replies

  • Hi,

    You can manage that by your self, take a look at this link and you will have all knowledge needed to achieve your goal :

    http://technet.microsoft.com/en-us/library/bb738124(EXCHG.80).aspx

    Good luck


    Best Regards Don't forget to mark it as answer if it helps
    Thursday, September 22, 2011 7:20 PM
  • Personally I don't think that adding more RAM is going to help things much. Not with 35 mailboxes. The size of the mailboxes doesn't really matter.

    The main area where you can increase performance is on the storage configuration, but as you haven't outlined the storage for this server, advising whether it is optimal is impossible to say.

    Are you seeing performance issues?

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.
    Thursday, September 22, 2011 10:06 PM
  • Simon,

    I forgot to mention the storage config. It is a RAID10 with 4 SAS disks. There are 2 storage groups, Mailbox db and Public Folder db (this server replaces an Exchange Server 2003).

    I don't see any performance issues as far as I can tell but it is only "visual" inspections (eg: Task Manager Performance tab or hard disks LEDs). There must be some other way to diagnose memory usage, disk usage etc but I'm not sure what to look at so I asked.

    As far as I know the RAM config satisfies the recommended memory size (8GB + 5MB per mailbox) for a multiple roles Exchange box.

    Thursday, September 22, 2011 10:37 PM
  • You have a SINGLE array? No other arrays at all? The OS isn't on its own array or anything?

    In that case you have a bottleneck. Exchange is a high transactional database that writes to two locations almost sequentially. If you have both locations on the same storage then it is basically thrashing against itself.

    Separating the logs and the databases on to their own spindles would make a significant difference to the performance of the server.

    I wouldn't go by the hard disk LEDs because Exchange is always accessing its hard disks. It isn't a quiet application.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.
    Thursday, September 22, 2011 10:43 PM
  • That is correct, only 1 huge array of 4 disks. If Exchange is always accessing its hard disks, the activity LEDs should be almost always constantly blinking. Not in my case though.

    Which performance counter should I look at to check if my storage performance is optimal or not?

    Thursday, September 22, 2011 10:51 PM
  • You don't have that many users, so the bulk of the storage work will be done client side if they are all in cached mode.

    No need to run performance counters - simply run the Exchange Performance Troubleshooter from the Toolbox. That will do all the work for you and tell you if there is a problem.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.
    Thursday, September 22, 2011 10:58 PM
  • I just ran Exchange Performance Troubleshooter with all default selections. There are no issues reported. All tabs (Overview, Performance Issues, General Info) show informational items (the I icon). No disk bottleneck detected either.

    There are a couple of red X icons under Execution Issues (tab), they are as follows:

    ExMon Tracing is not enabled
    ExMon tracing is not enabled on the server 'exchange2k7'.

    Failed to read ExMon data from the ETL trace file
    No user data was found in Exchange Server User Monitor (ExMon) ETL trace file 'C:\Perflogs\exchange2k7-20110922155940\exchange2k7-EXMON.etl'. This may be because you are not running this tool on a version of Windows that is the same or more recent than the server on which the trace was collected, or because there was no RPC data in the trace file.

    Not sure what they mean. I thought a server with 2 separate arrays on 2 different RAID controllers is an overkill for a small company with only 30 something users, don't you think so?

    Thank you very much for your quick replies.

    Thursday, September 22, 2011 11:30 PM
  • Exmon are just tools used by the Performance Tool. The fact that they are not enabled isn't an issue.

    My home server has two arrays, one for the OS/Logs and one for the database. And that has a grand total of five mailboxes and one user (me). I have clients with less users on dual arrays. You don't look really at the users at this level, but what they are doing with the data. 30 users with a 20gb store, not an issue. 20 users each with 20gb mailboxes, then you could benefit.

    If the performance troubleshooter didn't flag anything then I would simply forget about and leave it alone.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.
    • Marked as answer by morph2-7 Thursday, September 22, 2011 11:44 PM
    Thursday, September 22, 2011 11:36 PM