Hi
I just got done talking with support at Netapp, and they told me that doing an offline defrag of my exchange DB using the esutil will have absolutely no impact on the exchange DB on the filer, and they also told me that in order to defrag the exchange DB I must use the fillers Waffle utility to do this and that this would also defragment everything on the vol. They said that it's the responsibility of the file system on the filer to determine if a vol is fragmented or not, this includes all data on the vol. So knowing this is it safe to defrag a vol that contains an exchange DB??
Thanks again for your help it is much appreciated
Skip
-----Original Message----- From: Borders, Rich [mailto:Rich.Borders@netapp.com] Sent: Thursday, June 03, 2004 11:13 AM To: SKIP HOFMANN; toasters@mathworks.com Subject: RE: Defraging the excahgne DB
<<< I am replying in-line >>>
From: SKIP HOFMANN [mailto:SKIP.HOFMANN@ttisg.com] Sent: Thursday, June 03, 2004 1:33 PM To: toasters@mathworks.com Subject: Defraging the excahgne DB
Howdy
I have my exchange 5.5 DB pub and priv and my filler it's a FAS250 and I want to know a few things
#1 can I run the eseutil utility if the DB is on my FAS 250 to defrag the DB?
<<< This is doable as it is an offline defrag. The curious thing about doing this is that you are accomplishing the APPLICATION defrag, and at the same time getting a great by-product of a WAFL defrag. ( Essentially a database re-write ) >>>
#2 is it the filer that determines if the exchange DB is fragmented or not, and if it is how would I defrag the DB?
<<<The Application can fragment ( very common and accounted for by an online and offline defrag funciton in Exchange ) and the Filer can fragment. I say that tounge in cheek because the fragmentation is really only identified when you access the data. Since the database is one large file the request for data in it is atypical, the data 'fragments' over time. The blocks of the filer rarely match up to the blocks of the database, so the issues becomes when you want to get a LOT of sequential data from a large file ( aka mail store verify ) you will be essentially asking the filer to scan through it's blocks at a super high rate of speed.>>>
#3 what happens to all other data that is stored on the same vol as the exchange DB once I defrag this vol? ie snap shots
<<<The Mail store can be reallocated or the volume can. I would recommend the snapshots be removed as you can really get yourself into a pickle by 'RE'-writing a database with an application defrag, or a WAFL reallocate. If you are short on space, you need to get the snapshots out of there. Snapshots are locked images and if the file system is 'fragmented' then it is unlikely that you are doing much more than spinning your wheels if you are trying to defragment into a fragemnted snapshot. >>>
#4 I ran a waffle scan and I got a reading of 1.8 si this fragmented?
That is basically a ratio of actual file size ( df essentially ) to block allocation. Ex. A one terabyte volume has a 500 gig database. If it's layout is 1 then the File is essentially using the exact number of blocks that a Filer of 500 gigs needs. If the layout were 1.8 then the 500 gig df would still be 500 but the block allocation would actually be closer to the 900 gig . This is usually not an issue until the ratio takes the block allocation higher then the volume size. A 2.1 layout would mean that a 500 gig df would be 1.05 TB. This means you are rescanning on a request of data on the last .05 TB. If the Filer were a 900 gig df, then a layout of 1.8 would be MUCH more impactful. It is not the end of the world, you just have to manage it. You are on the right track I can see, so good luck.
Thanks a bunch
Skip
Rich Borders