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Date: Mon, 30 Mar 2009 11:12:14 -0700
From: Andrew Sharp <andy.sharp@onstor.com>
To: Jonathan Goldick <jonathan.goldick@onstor.com>
Subject: Re: Compression question
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Well, exchange doesn't do de-dupe for my definition of de-dupe, but
that's beside the point.  I've been told that compression is a popular
feature for exchange folks, but obviously I don't have firsthand
knowledge.  The text part of messages compresses quite a lot over the
entire database.  As for what compression exchange itself might offer,
I have no idea.  Perhaps my knowledge is out of date?  Compression of
attachments would be minimal as most are already compressed at the
client end.

On Mon, 30 Mar 2009 11:01:01 -0700 Jonathan Goldick
<jonathan.goldick@onstor.com> wrote:

> Are you sure about Exchange?  I ask because Exchange already does internal ddup and compression when it single-instances message fragments.  Now exchange backups I totally get, they ddup nicely.
> 
> 
> 
> -----Original Message-----
> From: Andy Sharp 
> Sent: Monday, March 30, 2009 10:51 AM
> To: John Keiffer
> Cc: John Rogers; dl-Leopard
> Subject: Re: Compression question
> 
> I really don't know the answer, but I have another question to throw
> into the mix.
> 
> Probably the biggest target application for both de-dupe and compression
> is exchange.  The question is, can compression be used for an iSCSI
> volume?  It would be very interesting to customers if we could tell
> them that they could expect in the neighborhood of X% compression of
> their exchange data.
> 
> Cheers,
> 
> a
> 
> On Mon, 30 Mar 2009 08:24:25 -0700 John Keiffer
> <John.Keiffer@onstor.com> wrote:
> 
> > It's my understanding that it would only apply to new data coming in. However, over time you would see a decrease in size since when existing data is accessed and re-written, it is written in a new place and would probably then have the compression applied. (Please correct me if I'm wrong.)
> > 
> > -John
> > 
> > ________________________________
> > From: John Rogers
> > Sent: Friday, March 27, 2009 5:08 PM
> > To: dl-Leopard
> > Subject: Compression question
> > 
> > Can I turn compression on, on an existing data set and expect that it will be compressed or does compression only apply to incoming data?
> > 
> > John
