Good to have you back Ed.

Serdar Soysal


-----Original Message-----
From: Woodrick, Ed [mailto:[EMAIL PROTECTED]] 
Sent: Friday, March 15, 2002 4:27 PM
To: Exchange Discussions
Subject: RE: eseutil /d


That does sound like my argument....


First in looking at the arguments, it helps to understand what you are
arguing. Somewhat as stated, your team is right defragmentation should be
done on a regular basis. It reduces the number of extensions on messages,
but more importantly makes it faster and easier to find free space to store
the messages. 

Exchange's database is just like any current art database. It's a
transaction oriented, journal led write database. Nothing really spectacular
about it, regular database maintenance is all that is really needed. So you
can easily go to a DBA and get suggestions on how to best care for a
database.

In most large database products, take SQL for example, as you create a
database, you give it an initial size and then specify if the database is
extensible or not and if so, how big is an extension. A common default that
I use is 50MB for the initial size and 5MB extensions. Then on a regular
basis, the database should be defragmented, and then, once in a blue moon
you might want to reload the database, although it's not often done anymore.


That's the same with Exchange, you want to defragment the database regularly
and then reload it on a extremely rare, probably never basis.

Sounds good?

Install Exchange 5.5 and let it do it's thing and that's what you've got.
Nightly, the system makes two runs through each database to defragment it.
It also runs through each page of the database to make sure that the
checksum is correct as you perform a backup. And I believe that another
process goes through and validate the structure periodically.

So why run eseutil/d?  Well, when I was talking about databases growing,
noticed I never said shrinking. SQL doesn't shrink a database, neither does
Exchange. Biggest reason is because there really isn't a need for it in most
cases. How many people hear of their total storage decreasing? It's usually
at least a 5-10% a year increase. But, there are situations where indeed
your database could decrease dramatically. That would be if you put a new
storage policy into effect, although with the dumpster it could be a few
weeks before the messages are actually deleted and SIS can also impact it.
Or if you've added a new server and moved users to it. There are a variety
of reasons why you would have gained a lot of white space in your database.

The question that you need to ask yourself is "are you going to use it
again?" If you've deleted some users or objects and you've created 1-%
additional white space, just how long do you expect it to be before the
space fills back up? If it's a few months, don't worry about it. I tend to
make a few GB or 10% of the total store, whichever is higher, the number at
which I even start thinking about repacking. I saw last night that I've got
50MB of white space in one of my DBs. It's not even on the radar screen to
be compacted. If I had 5GB of white space on a 50GB database, then I might
start looking for a window to compact it. But remember that it's going to
take a few hours of downtime to do it.


Eseutil /d is really a misnomer, a hangover from earlier days. For Exchange
5.5 and later, it really should be eseutil /c or "compact" While it does an
applied defragmentation, the database is seldom fragmented, because it is
defragmented twice every evening.


Oh, and if you do compactions on a regular basis to the same disk, you are
probably going to get some ugly NTFS fragmentation.

(And yes Daniel, if you compact your database, the system is going to take
extra overhead to have to expand the database. And compared to writing a
single object, I suspect that it's a rather lengthy process. Okay, it's
probably a hundredth of a second, but when you compare it to ill-advised
behavior like compacting regularly, at least it make sense)

But the real reason why not to do it is like everyone has said, there is
nothing to be gained, and a lot to be lost. It is NOT REQUIRED and NOT
SUGGESTED to obtain 99.999% uptime. Matter of fact, doing it brings you down
to about 99.5% uptime, just taking 4 hours per month.

As to making an Exchange Server reach 100% uptime, the equation is pretty
simple.... 

Keep the Hands Off!!!!!

(This assume nightly full backups and verification that the backup ran
--VERY important!)




Sorry folks, not enough time to give you the long version :-)


-----Original Message-----
From: William Lefkovics [mailto:[EMAIL PROTECTED]] 
Posted At: Friday, March 15, 2002 3:34 PM
Posted To: Microsoft Exchange
Conversation: eseutil /d
Subject: RE: eseutil /d


I remember that.

Mr Woodrick was pushing the envelope there.  With the whitespace taken away,
Exchange would have to take back diskspace as the database began to grow
again.  The resources required for that would likely not be noticeable.  :o)

But of course he was correct.

William

-----Original Message-----
From: Ray Zorz [mailto:[EMAIL PROTECTED]]
Sent: Friday, March 15, 2002 10:06 AM
To: Exchange Discussions
Subject: RE: eseutil /d


I remember an excellent explanation of how this will actually hurt Exchange
performance by one of the Ed's.  I saved it, then lost it somehow. Maybe
someone still has it.

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Couch, Nate
Sent: Friday, March 15, 2002 10:54 AM
To: Exchange Discussions
Subject: RE: eseutil /d


Try reading Jim McBee's book - Exchange 247.  It talks about this very
issue.  Basically, it comes down to the view, from my reading, that "if it
ain't broke - leave it alone".  If you aren't seeing any errors in the Event
logs that clue you into a problem with the databases don't go begging for
trouble - you are likely to find it.

All the best in your battle with your coworkers.

Nate Couch
EDS Messaging

> ----------
> From:         paragon400
> Reply To:     [EMAIL PROTECTED]
> Sent:         Friday, March 15, 2002 11:32
> To:   [EMAIL PROTECTED]
> Subject:      eseutil /d
>
> I have some team members here that believe that regular
> defragmentation
> (offline) should be done as routine maintenance.  I don't share this
> opinion, but I am having a hard time finding evidence to support my
> belief.  Does anyone know of any links that support the theory that
> eseutil should not be used for regular maintenance or am I wrong and
> should it be part of regular maintenance?
>
> Exchange 5.5 environment.
>
> Thanks for any help anyone can provide.
>
> _

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