[itdiscuss] Exhange Defrag

[Kevin Brunson]

I agree that running a disk defrag on a running Exchange store is not the best idea.  However, I think I need to clarify something.  Disk defrag and eseutil are serving two different purposes.  Eseutil moves data around inside the database file to make sure it is all contiguous IN the file, and disk defrag makes sure that the sectors containing the files are all contiguous ON the disk.  As an Exchange database file grows, it can get spread all over the disk just like any other file.  Running eseutil for a database on a fairly full disk actually has the potential to make the database files significantly more fragmented, even if the data inside those files is made more contiguous.  Windows has to find a place to put those files when it makes them or expands them, and that may mean filling gaps on the hard drive.  If the drive is dedicated to Exchange databases you are less likely to find fragmented DBs, since the only thing on there will be DBs, but it is still possible.
A disk defrag will almost certainly not be able to defrag the Exchange DB files while the DB is mounted, and if it could that could result in a damaged DB.  So if you want to run a disk defrag, I would suggest you dismount the DB or stop the services.

Kevin Brunson

From: discuss-bounces at itdiscuss.org [mailto:discuss-bounces at itdiscuss.org] On Behalf Of Jason Hand
Sent: Tuesday, May 26, 2009 1:14 PM
To: 'IT Discussion Forum'
Subject: Re: [itdiscuss] Exhange Defrag

I would not try a defrag on a volume with the exchange store on it while in production.  The store is just a couple of large database files and are not defragmentable except for what you mentioned, eseutil.  As for the other files, surely they are not causing performance problems for Exchange.

JKDefrag works well and I have used it on file servers and workstations with success.  Since it runs as a command-line utility it works very well and is easy to schedule via the Task Scheduler.

Defragmenting can help in situations where the drive is being used to do lots of read/write access to the files stored on it like a File server but since Exchange is like any other database system it houses it's files in 'containers' and therefore doesn't really benefit from the rest of the drive being defragmented.

-Jason

________________________________
From: discuss-bounces at itdiscuss.org [mailto:discuss-bounces at itdiscuss.org] On Behalf Of Stephen W. Klose
Sent: Tuesday, May 26, 2009 1:57 PM
To: discuss at itdiscuss.org
Subject: [itdiscuss] Exhange Defrag
Are there any issues with running a file level defrag on drive that also has the Exchange Server Stor?

I know there is eseutil, but at the same time, there are other files on the drive that are fragmented and affecting performance.

Here are some links that indicate it is okay, but I have seen warnings on the subject as well:
Microsoft Help Article: http://support.microsoft.com/kb/328804
Article with user comments: http://msexchangeteam.com/archive/2004/10/25/247342.aspx

Also: Does anyone know of any issues with jkdefrag? (open source alternative to the windows defrag)

Thanks,

Steve Klose
Altadena Valley Presbyterian Church
Cell: 205.427.5420
Home: 205.987.7545
Pager: pager at klose.cc<mailto:pager at klose.cc>


No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.339 / Virus Database: 270.12.40/2135 - Release Date: 05/26/09 08:53:00
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://optimus.thompsonic.com/pipermail/discuss/attachments/20090526/3c2d1714/attachment.htm