admins will tell you that offline defragmentation of an Exchange database i=
s generally not recommended unless you have just purged a large amount of d=
ata or mailboxes and need to reclaim that disk space. Exchange runs regular=
online defrags to reorganize data within the database, without actually ch=
anging the size of the database file, which keeps things performing well. I=
f you run an offline defrag to compact the size of the database, Exchange w=
ill just grow it the next time it needs more space, and that growth process=
is IO intensive. This will slow down your system, and in turn will also in=
troduce fragmentation issues if the volume is shared with other data. Aside=
from these implications, offline defrags have the potential to introduce d=
ata corruption, as eseutil isn't exactly a stable, well written tool.
Ed Crowley, the infamous Exchange administrator for HP (25k mailboxes) used=
to rail against offline defrags on many of the Exchange lists going back t=
o 1997. I can't for the life of me find one of his very well written respon=
ses to this topic, but suffice it to say anyone who maintains 25k mailboxes=
on Exchange for one of the largest technology companies in the world has m=
y vote of confidence.
S
-----Original Message-----
From: A forum for independent school educators [mailto:ISED-L@LISTSERV.SYR.=
EDU] On Behalf Of TJ Rainsford
Sent: Tuesday, June 22, 2010 3:01 PM
To: ISED-L@LISTSERV.SYR.EDU
Subject: Re: Public Folders Exchange 2003 and iPhones
Renee:
If only it were that simple :-)
In order to reclaim disk space and white space when users clean up email,
you actually have to run a offline defrag of the Information Store in
Exchange. This is actually something that should be done on a regular basi=
s
as part of maintenance (the interval is dependent on the how big your
information stores are). It is a pretty straight forward task but must
necessarily be done after hours as it will take down any users who are part
of the specific information store as long as the process is running.
Running regular offline defrags is a really good idea. Not only will it
clean up disk space, it will compress the information stores (and defrag
them) which will improve overall performance and keep the system happy.
Please note that this is NOT a disk defrag! In fact, running a disk
defragmentation process on the disk where your Exchange data resides is a
fundamentally BAD idea (things will likely go BOOM in a really bad way).
And as with all major maintenance, make DARN sure you have a backup of
EVERYTHING (the OS, server system state, Exchange databases, etc) before
doing this.
TJ
TJ Rainsford
E: tjrainsford@gmail.com
[ For info on ISED-L see https://www.gds.org/podium/default.aspx?t=3D128874 ]
Submissions to ISED-L are released under a creative commons, attribution, non-commercial, share-alike license.
RSS Feed, http://listserv.syr.edu/scripts/wa.exe?RSS&L=3DISED-L
