Veritas-bu

[Veritas-bu] SSO and Multiplexing Question

2007-01-17 18:12:22
Subject: [Veritas-bu] SSO and Multiplexing Question
From: Jason.Ellis at indymacbank.com (Ellis, Jason)
Date: Wed, 17 Jan 2007 15:12:22 -0800
Thanks to all who responded. I should note that when I'm trying to
"maximize throughput" on my drive we are backing up a SAN attached
drive, not a client over the network, so I don't want the multiplexing
to be the same as what we do per our LAN jobs. In the end I will
probably end up doing multiple streams from this SAN attached drive
(actually a volume with multiple spindles, so I should be thrashing the
heads - one hopes).

Thanks again!

Jason Ellis
Technical Consultant, Data Protection Team
IndyMac Bank, La Mirada Datacenter
Phone: (714) 520-3414
Mobile: (714) 889-8734


-----Original Message-----
From: Tom Burrell [mailto:tburrell_mn at yahoo.com] 
Sent: Wednesday, January 17, 2007 12:00 PM
To: Ellis, Jason; veritas-bu at mailman.eng.auburn.edu
Subject: Re: [Veritas-bu] SSO and Multiplexing Question

Jason,
You're conclusion is correct as to the effect of
disabling multiplexing, but I question your logic for
doing so.  

Disabling multplexing does not "maximize drive
throughput" during a backup.  That is what
Multiplexing is actually set up to do.

I'm not a big numbers guy, so I'll let others step
through the math, but I can tell you in my real-world
experience that in a properly configured Netbackup
system, multiplexing to tape is not going to slow you
down- it will actually help especially if you look at
the environment as a whole.

The only thing it buys you really is less
fragmentation  on the tape. If that's important then
fair enough- but try and shim some Disk Staging in
there if you can- the staged data can be written to
the tape faster than the raw data from the client (in
most cases).

 Tom Burrell



--- "Ellis, Jason" <Jason.Ellis at indymacbank.com>
wrote:

> If I have maximum multiplexing set to 8 on one
> storage unit A, and 1 on
> another storage unit B that are sharing drives in
> SSO, then if a job
> starts to run using storage unit B will it only run
> one stream to the
> drive until that job has been completed?
> 
>  
> 
> Basically I want to prevent multiplexing to drives
> in SSO only from one
> storage unit to maximize drive throughput for a
> specific job.
> 
>  
> 
> Jason Ellis
> Technical Consultant, Data Protection Team
> IndyMac Bank, La Mirada Datacenter
> Phone: (714) 520-3414
> Mobile: (714) 889-8734
> 
>  
> 
> > _______________________________________________
> Veritas-bu maillist  - 
> Veritas-bu at mailman.eng.auburn.edu
>
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
> 



 
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