Veritas-bu

Re: [Veritas-bu] Has anyone done benchmarking of any sort with..

2007-07-27 09:14:31
Subject: Re: [Veritas-bu] Has anyone done benchmarking of any sort with..
From: Justin Piszcz <jpiszcz AT lucidpixels DOT com>
To: Kevin Whittaker <Kevin.Whittaker AT syniverse DOT com>
Date: Fri, 27 Jul 2007 09:01:44 -0400 (EDT)
VTLs seem nice in this regard then :)

Justin.

On Fri, 27 Jul 2007, Kevin Whittaker wrote:

> Ah... Yes I see where you are going.... But my way will just put the
> image on the tape, no multiplexing at all.  I have a Virtual Tape
> Library, and I am in the process of creating 5 robots with 20 drives
> each.
>
> To avoid multiplexing you have to dedicated a drive to each channel, and
> that is what setting the MPX=1 does.
>
> When you are limited on tape drive resources.... You can not do this.  I
> used to just have my L700 with 11 9940B drives, and could have never
> considered this with the fact that I backup over 35 databases.  But now,
> with the VTL I can configure as many drives as I want to configure.
>
> So to answer the question, un multiplexing will commit 1 drive to each
> channel.  You can not multiplex different backups onto the same drive at
> the same time.
>
> Kevin
>
> -----Original Message-----
> From: Justin Piszcz [mailto:jpiszcz AT lucidpixels DOT com]
> Sent: Friday, July 27, 2007 8:46 AM
> To: Kevin Whittaker
> Cc: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: RE: [Veritas-bu] Has anyone done benchmarking of any sort
> with..
>
>
>
> On Fri, 27 Jul 2007, Kevin Whittaker wrote:
>
>> Oh... Sorry about that.
>>
>> That is the easy part.
>>
>> Under the Schedule, within the policy, I changed the media
>> multiplexing to 1.  The RMAN script starts 4 channels, and sees the
>> schedule says only 1 multiplex then it sends them to different tapes.
>
> This is good in a sense, but say you have 10 tape drives for example.
> If you are multiplexing other backups with the DB backups, does the RMAN
> policy write with LEVEL 1 multiplexing to separatae tapes and the other
> backups still take place for the other (assume MPX=4) 3 levels of
> multiplexing on the drive? Or does the MPX=1 job utilize the entire tape
> drive?  Does it make sense what I am mentioning?
>
> Essentially you'd want separate tape media IDs for each server but you
> still want other servers writing for the other 3 levels of MPX on that
> tape.
>
> Justin.
>
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