Hi Kelley,
     Would you explain what the mechanism is that performs the reconcilation of
the 2 lists? I'm particulary interested in the
"whacker" since that probably is what's hogging my resources.
______________________________
Subject: excessive run times
Author:  acourcha (acourcha AT csc DOT com) at unix,mime
Date:    7/6/98 7:32 AM

Hi All,
     Does anyone have any idea what would cause extremely long run times for
backups that run from schedules? I have 9 AIX Clients that are attached to an AI
X
server. Normally I backup 6 over the weekend and 1 each on Sunday night thru
Wednesday night For the long weekend, I setup a schedule that would backup all 7
clients over a three day time period. As an example, one client, Node7, normally
completes in 20 minutes but it took 13 hours when run in a multiple client
schedule. Has anyone experienced this and what is the cause?
Thanks in advance for any theories, hints, tips or helpful suggestions
Ann Courchaine
Senior Consultant
Year 2000 National Practice
Consulting & Systems Integration
91 Hartwell Avenue
Lexington ,MA 02173



Date:    Mon, 6 Jul 1998 08:12:25 -0600
From:    "Kelly J. Lipp" <lipp AT STORSOL DOT COM>
Subject: Re: excessive run times
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How many files in the filesystems?  It could be excessive database activity
during multi-client backups, especially during the deleted file processing
that occurs at the end of data movement.  The server and client reconcile
the filespaces after moving the incrementally changed data.  Essentially,
two lists are built in the client: one of all the files the client thinks
it has and one with all the files the server thinks the client has. It's
this second list that whacks (technical term) the database and can consume
large amounts of time.  I would think with more than one client doing this
at a time, the whacks would be quite bad and would tend to slow the whole
mess down.
In V3, you have the option, at least in the windows clients, of performing
a "fast" backup that does not perform the deleted file processing.  The
downside to this is you may get deleted files back during a complex
restore.  However, in general, too much data is better than too little.
 I've also seen situations where most of the time, say during the week, the
deleted file processing is skipped and then performed once a week.  In your
situation, you could have one node per night perform the entire backup
while having the others skip this step.  Your exposure is somewhat limited
as all nodes get to perform deleted file processing at least once per week.
Or, I could be all wet and the symptoms you are experiencing are totally
unrelated.  Early Monday!


Kelly Lipp
Storage Solutions Specialists, Inc.
lipp AT storsol DOT com
www.storsol.com
(719) 531-5926
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