With VTL there is no need to multistream.

Instead of writing 8 stream to 1 drive, just create 8 Virtual drives,
and not multiplex.

It's not because of a performance issue, it's an advantage of
virtualization.

As far as performance goes, with a Disk as disk config, to create a high
perf target, you would need to create HLUNs which are striped over many,
many LUNs on your array, or present LUNs which are stripes of segments
of many RAID groups.

Many VTLs (the one I'm using, for instance) distribute the writes over
many LUNs. I'm currently writing dozens of simultaneous jobs distributed
over 28 separate LUNs.

The data reduction (compression) & throughput I'm getting with VTL is
definitely better, on a "per client job" basis than I was getting to
MPX'ed jobs going to LTO2.

Offsite is SUPER easy....we replicate our LUNs caontaining the de-duped
data to our DR site.
To bring up the other site, once the DR LUNs are made R/W, we just start
the daemons on the DR VTL and away we go.
The devices are available there as they were at head office.

Don't even need to rediscover devices on the NBU servers.

Vault works great for spinning off copies to Physical tapes, if
necessary.

Paul


-- 


> -----Original Message-----
> From: veritas-bu-bounces AT mailman.eng.auburn DOT edu 
> [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf 
> Of Clem Kruger
> Sent: September 22, 2007 5:12 AM
> To: Jeff Lightner; Justin Piszcz
> Cc: veritas-bu AT mailman.eng.auburn DOT edu
> Subject: Re: [Veritas-bu] Tapeless backup environments?
> 
> Compression on a VTL is done by the operating system (normally LINUX)
> which we all know is a slow process and therefore not 
> recommended. Your
> VTL supplier will also recommend that you do not multistream as this
> also slows down the process.
====================================================================================

La version française suit le texte anglais.

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