Re: [ADSM-L] Exchange 2010 and TDP / VSS

2011-01-26 09:41:34
Subject: Re: [ADSM-L] Exchange 2010 and TDP / VSS
From: "Hart, Charles A" <charles_hart AT UHC DOT COM>
Date: Wed, 26 Jan 2011 08:14:51 -0600
Thank you Del,  Yes I meant quiesced just couldn't type.  Really
appreciate the insight.



-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Del Hoobler
Sent: Tuesday, January 25, 2011 6:51 PM
Subject: Re: [ADSM-L] Exchange 2010 and TDP / VSS

>> I browsed the fine manual but was hoping to gain a little insight 
>> from other experiences.  I understand that it's no longer a streaming
>> it's a VSS software snap.  Does anyone know how long the Exchange 
>> DB's are in a guessed state?

Do you mean quiesced state?
Writes to the disk are suspended for less than 10 seconds (Microsoft
requirement), but Exchange continues to be able to service requests.

>> Does it depend on the DB size or does VSS get a snap and then tsm 
>> backs the snap?

Once a snapshot is created, there is logically a "static" copy of the
volumes that the the database and logs are on. At that point, TSM will
perform the integrity check (Microsoft requirement) and then back the
files up to the TSM Server. The integrity check and backup is performed
on the snapshot volume.
The VSS Provider that you use will determine what the physical
representation of that logical volume snapshot is.
If you do not install a VSS Hardware Provider from the disk vendor that
you are using, the Microsoft "in box" VSS System Provider is used. The
the Microsoft "in box" VSS System Provider is a software-based,
"copy-on-write" implementation.

>> If the DB is guessed for the duration of the backup then maybe it 
>> makes sense to backup just the passive

Again, I assume you mean "quiesced" state...
Microsoft and IBM recommend that you perform the backup from the passive
DAG copies to help "offload" the hit to the production servers.

>> Any thoughts or insight would be great!

Take a look at this. It is a blog that I wrote that gives you some links
that help explain what VSS is and how TSM works with VSS.

>> Regards
>> Charles




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