Thanks, Del.

My comment  regarding living with an incomplete/incorrect point of
recovery was solely meant to represent that in a complete data center
wipe-out, the existing full and incrementals that we have offsite would
not accurately represent what was in a particular mailbox at the time of
the backup.  Since TDP doesn't backup a log file unless it is filled (and
I assume that means if a log file is open, the TDP doesn't backup that
information in those logs).  If somehow, TDP is able to get this
information from the currently open log files (four per storage group, or
is it four per mail store), then we will be OK.

Thanks again.. I will be testing how all this works as soon as we can.
Todd





Del Hoobler <hoobler AT US.IBM DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
06/24/2004 10:39 AM
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Fax to:
        Subject:        Re: TDP, Exchange 2003, and SANs


Todd,

Answers embedded.

Thanks,

Del

----------------------------------------------------

"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 06/24/2004
11:17:55 AM:

> Del,
> Thanks.. follow up question...
> You said...
> >>
> Data Protection for Exchange performs incremental and
> differential backups by backing up the full
> transaction log files to TSM. They are all placed into a
> single TSM backup object.
> <<
>
> From this, would it be safe to assume that the data from hundreds of 5MB
> log files would stream well across the SAN, since your description
infers
> that the incr would be handled with a single TSM database transaction?
> Does the txngroupmax value have any bearing on this?

There are always various factors that can influence this,
however, in theory, you are correct. These will be represented
by a single stream of data being backing up to a single TSM object.
"txngroupmax" will not affect this since it is a single TSM object.
My best suggestion is to try it to see how it performs for you.


>
> You said the incr/diff backup only backs up the full transaction log
> files.  That concerns me a bit.  The Exchange admin indicated that
> Exchange has four log files open at all times.  This means that up to 20
> MB of transactions would not get backed up during a backup (full
> included).  We are new to Exchange, migrating from Domino (plea$e,
plea$e,
> don't a$k me why we would even what to do that... it'$ a long $tory).  I
> guess we will have to just live with the incomplete/incorrect point of
> recovery.

You don't need to "live with" anything. You don't need to
be concerned, either. Data Protection for Exchange works
directly in conjunction with the Exchange server through
the Exchange backup API. The Exchange Server tells Data
Protection for Exchange which logs files need to be backed up.
Data Protection for Exchange takes that list and backs them up.

You don't need to worry about an "incomplete" backup, either.
Since Data Protection for Exchange uses the Exchange backup API,
all of your backups will be completely consistent.

>
> Thanks again for the quick and informative reply,
> Todd
>