David..  I agree with your comments.  We have a serious reliance on
restoring data from tape rather then grow our online copies to a sufficient
level where we can do disk restores.  That being said, when we tested
multiplexing we saw almost a doubling of the restore time from what it
normally took in a single stream backup.
This was unacceptable to the user community so MPX was not an option for us.

Martin


-----Original Message-----
From: david AT dsihost-srv01 DOT com [mailto:david AT dsihost-srv01 DOT com]
Sent: Tuesday, May 21, 2002 7:41 AM
To: John Meyers
Cc: 'veritas-bu AT mailman.eng.auburn DOT edu'
Subject: Re: [Veritas-bu] Multiplexing


John you are absolutely correct!  I have no benchmark data but I don't think

you really need it to argue that a restore of a single contiguous stream
will 
be faster than that of its peer that has been Multiplexed with 8 other jobs.


However, I believe that is something that needs to be decided at the
Business 
level with regards to each individual site's SLA they have with their
customers 
(user community).

David


Quoting John Meyers <john.meyers AT wright DOT edu>:

> 
>  Regarding performance issues with multiplexing, I would think that the
>  higher the number of streams multiplexed to a tape, the slower your 
>  restore times would be due to the extra tape positioning required.
> 
>  I was just wondering if anyone had any data in this area regarding
>  performance metrics associated with multiplexing multiple streams to
>  tape?
> 
>  Thanks,
> 
>  John
> 
> --
>  John Meyers
>  Computing Services
>  Wright State University
>  E-mail: john.meyers AT wright DOT edu
> _______________________________________________
> Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> 



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