Re: Exchange maintenance after loading/deleting messages. by SuperGumby
SuperGumby
Thu May 15 08:38:46 PDT 2008
and just why does Exchange commit all this memory/filespace and not want to
give it back?
Exchange is, basically, an RDBMS (Relational Database Management System). In
some ways the fact that it handles email is a secondary consideration, as
far as Exchange is concerned it's 'DATA'. A basic principle of RDBMS design
is that 'if it was accessed it will probably be accessed again', a high
percentage of 'queries' are satisfied by looking only at recently accessed
information. So, Exchange keeps as much of this 'recently accessed' in
memory as it can.
The file side of things is similar but has a twist. If Exchange has room in
the database to store incoming info (new messages) it can do so without
calling 'gimme another block of filespace', without adjusting its indices to
accomodate that new block. And those indices are important, fragment those
indices by perpetually growing/shrinking them and they get spread all over
RAM and filespace, here's part of the table and we will now jump somewhere
else and give you the next part of the table, and the next, and the next...
SBS suffers a little from this. What works well for an 'enterprise' with
several hundred Exchange users maybe doesn't work as well when Sam can turn
to Sally and say 'I just got that contract confirmation', but look at how
you use email. I know I work with Exchange, most of what I access is less
than 24hrs old. Yes I search for older stuff, need it at times, have
projects that take weeks (if not months), but still 'if it was accessed it
will probably be accessed again'.
"Cary Shultz" <cshultz@nospam.outsourceitcorp.com> wrote in message
news:Ot4S5smtIHA.4772@TK2MSFTNGP03.phx.gbl...
> Roveer,
>
> I think that I am probably a bit more verbose than you!
>
> One of the things - if I might speak for others at the moment - that I
> noticed when I was an MVP for Active Directory is that most people do not
> search the news group before posting a question. Now, not saying that you
> are doing this...just a very very very general comment. That used to
> drive me a bit crazy. Mind you - the exact same question! Not 90% the
> same with a decided twist...the exact same question. In fact, I remember
> one time that the same question was posted by three different posters in a
> row.
>
> Another thing that I noticed is that there are people who just do not
> listen. Again, not saying that pertains to you. Just a very very very
> general comment. That gets a bit frustrating for the people who pretty
> much live in this or that news group. I think that you will find that
> there are probably eight or 10 people who live in here. These - along
> with others - know SBS inside and out. They also, well, like I already
> said, live in this news group so they probably already know the issue and
> the solution before you ask.
>
> One more thing is that these eight or 10 people (as well as a lot of
> others) have a very good basis of knowledge and can tell when someone is
> going down the wrong path. I do this myself. I have been doing this for
> 11 years and have my own way of doing things. I know a thing or two -
> mostly from bad decisions. So I have a pretty good idea when someone is
> trying really hard to go down the wrong path. I try to nudge those in the
> 'better' direction. But, as we all know, every environment is different.
> I have been introduced to environments that are literally hanging on by a
> band-aid. If you 'fix' things then all you are going to do is to break
> pretty much everything.
>
> Anyway, everyone in here is doing this on his/her own time and - for the
> most part - because he/she loves doing this. MVPs do not work for
> Microsoft. Sometimes, Microsoft gets tired of hearing from MVPs. We
> (well, not 'me' anymore.....) can be pretty harsh with Microsoft at times.
>
> I started out like you did.....asking a ton of questions. There is
> nothing wrong with spending a lot of time in here and in a lab. In fact,
> this is what I would really suggest that you do. Create a lab environment
> with a couple of machines and play. And, don't be afraid to ask a
> question. If you have it then you can rest assured that there are a whole
> slew of others who have the same - or similar - question. You will also
> get to know whose answers you can trust and whose you can not.
> Unfortunately there are a few who give really bad answers intentionally.
> Someone with limited experience might try to implement 'that bad answer'
> and really find himself/herself in a bind. Those whom you can trust do a
> pretty good job of making everyone aware of those few bad apples.
>
> I spend a little bit of time in here as we manage several clients with
> SBS2003. SBS2003 is its own animal and has its own way of doing
> things....the first three rules of thumb with SBS2003: use the wizards,
> use the wizards and, finally, use the wizards! I stole that from someone
> in here! As you can see from the hour of this post I am up early. Just a
> ton of work!
>
> Anyway, I think that you will find that most regulars in here have a very
> strong opinion and are not afraid to voice it. All in all, it is a really
> good group of people who frequent this ng and I am sure that you will find
> lots of good, sound advice in here.
>
> Cary
>
>
> "Roveer" <noemail@noemail.com> wrote in message
> news:pYIWj.10055$mc1.6923@trndny08...
>> Larry Struckmeyer [SBS-MVP] wrote:
>>> Roveer, I apologize. A very similar question was answered recently,
>>> but I checked your previous posts and did not find one from you. I hope
>>> you are not too put out, and I promise never to do that again without
>>> double checking the source.
>>>
>>> Now, I stand by my comment. Leave it alone unless you *really* really*
>>> need the space. Shrinking it will just clear out the white space, and
>>> then it will have to grow again.
>>>
>>
>> Larry,
>>
>> No offense taken. I do get a bit verbose in my posts and at times do ask
>> very similar questions. I'm just trying to make sure that after all the
>> claims I've made about why we should be using a server and exchange that
>> some small insignificant item that I overlooked doesn't come back to bite
>> me. I often come off as a bit intense, especially when I'm hunting
>> technology related knowledge.
>>
>> All that being said, I want to thank everyone on this group for providing
>> such good information and sharing their experiences. I can tell you that
>> I've learned volumes in the past months and feel very comfortable in the
>> decision I've made to go to SBS. The list of features that we are going
>> to use right from the start is impressive and will have a positive impact
>> in our office. I'm just glad I had such a good resource to come to and
>> that so many of you are willing to take the time to post and reply to our
>> posts to help out. After all many of you make a living doing this and
>> here you are helping for free. Pro Bono. My thanks.
>>
>> Now, I have read up on the maintenance, and I took the advice from the
>> first reply and used the event viewer to inspect exactly what the nightly
>> maintenance was doing. I see that when the messages & mailboxes hit
>> their retention limits they will be removed. This gives me a good
>> feeling that exchange is doing it's thing. This was a very beneficial
>> exercise. Oh, I see I've gotten verbose again. Just my thing I guess.
>>
>> Larry, we're all good.
>>
>> Roveer
>
>