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Exchange db/logs reads and writes query RRS feed

  • Question

  • On an Exchange 2007 Server, we have 5 SG's. Each SG has one Store only.

    I would like to measure the amount of disk activity and get a baseline in case we need to reference this during times of trouble.

    Questions -

    1. Am I correct in thinking that

    - The logs would be very write intensive but not read intensive-. The DB would be very read intensive but not write intensive


    2. Does it mean anything if the logs are read intensive and the DB is write intensive too?

    3. Should the activity be constant or spiking all the time?

    4. What should I be looking for if there is a problem?

    On a Windows 2008 Server, SCC cluster.
    Wednesday, April 6, 2011 9:10 PM

Answers

  • 1.  Generally yes.  Transaction log volumes are much more write intensive than read.  Database volumes are more read intensive than write, but less so.

    2.  What are you asking?

    3.  It depends on your user load profile and whatever else is going on, such as online store maintenance.

    4.  It depends on the problem.  As to storage subsystem measurements some of the most useful are Logical Disk\Avg. Disk sec/Read and Logical Disk\Avg. Disk sec/Write.  Another very useful counter is Database\Log Record Stalls/sec.  Be aware that your particular storage subsystem may cause some of these figures to report differently; consult your vendor for guidance.


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    • Marked as answer by emma.yoyo Wednesday, April 13, 2011 1:28 AM
    Wednesday, April 6, 2011 11:47 PM
    Moderator
  • You can reference the perfmon baseline metrics below.

    Monitoring Mailbox Servers

    http://technet.microsoft.com/en-us/library/bb201689(EXCHG.80).aspx


    James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
    • Marked as answer by emma.yoyo Wednesday, April 13, 2011 1:28 AM
    Thursday, April 7, 2011 2:43 AM

All replies

  • 1.  Generally yes.  Transaction log volumes are much more write intensive than read.  Database volumes are more read intensive than write, but less so.

    2.  What are you asking?

    3.  It depends on your user load profile and whatever else is going on, such as online store maintenance.

    4.  It depends on the problem.  As to storage subsystem measurements some of the most useful are Logical Disk\Avg. Disk sec/Read and Logical Disk\Avg. Disk sec/Write.  Another very useful counter is Database\Log Record Stalls/sec.  Be aware that your particular storage subsystem may cause some of these figures to report differently; consult your vendor for guidance.


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    • Marked as answer by emma.yoyo Wednesday, April 13, 2011 1:28 AM
    Wednesday, April 6, 2011 11:47 PM
    Moderator
  • You can reference the perfmon baseline metrics below.

    Monitoring Mailbox Servers

    http://technet.microsoft.com/en-us/library/bb201689(EXCHG.80).aspx


    James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com
    • Marked as answer by emma.yoyo Wednesday, April 13, 2011 1:28 AM
    Thursday, April 7, 2011 2:43 AM