I think we are licensed per TB on the VTL....not per drive.  

 

Our rationale in doing the multiplexing to the VTL was to increase
throughput to the VTL for backups.  We CAN increase the number of virtual
drives instead and then do single streams to the VTL and avoid the
de-multiplexing during the duplication step.

 

However, we are seeing lightning-fast read speeds off of the VTL regardless
of the fact that it is multiplexed (around 130MB/sec).

 

So, I'm still concerned about the speed with which we write out to the
physical tapes.....not sure where the bottleneck is...but there definitely
is a bottleneck.

 

  _____  

From: veritas-bu-bounces at mailman.eng.auburn.edu
[mailto:veritas-bu-bounces at mailman.eng.auburn.edu] On Behalf Of Paul Keating
Sent: Tuesday, September 19, 2006 8:49 AM
To: veritas-bu at mailman.eng.auburn.edu
Subject: Re: [Veritas-bu] LTO3 throughput on Vault/Duplication jobs

 

My thought's exactly JR.

 

I'm thinking folks either have VTLs where they are licensing from the vendor
on a "per virtual drive" basis, OR, they are licensing Netbackup on a (old)
per drive, rather than (new) per TB of usable disk basis, so want to avoid
the licensing cost of adding more virtual drives......that was on of my
primary criteria in selecting a VTL....I want to be able to create as many
virtual drives as I want.

 

I currently have 20 physical drives, and run various multiplex levels for
different STUs, depending on the type of backup, in order to maintain
sufficient data flow to stream the drives, but when the VTL comes into play,
I want MPX=1, so I'll be configuring upwards of 20 virtual drives per media
server.

 

Paul

 

 

-- 

-----Original Message-----
From: Dyck, Jonathan [mailto:Jonathan.Dyck at cognos.com] 
Sent: September 19, 2006 10:09 AM
To: Paul Keating; Liddle, Stuart; veritas-bu at mailman.eng.auburn.edu
Subject: RE: [Veritas-bu] LTO3 throughput on Vault/Duplication jobs

Agreed.  Coming from an environment where we are "afraid" of multiplexing
everything due to those image's importability (or lack thereof), the fact
that we cannot demux quick enough has us handcuffed a little.

 

Just a question, what's the rationale on mpx'ing to your VTL's?

 

Cheers,

Jon

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