Compression is nice, but many VTLs take a large performance hit doing
compression.

The killer feature of VTLs is data de-duplication, which is beginning to
be available.


Orville L. Lantto
Storage Consultant
 
 
GlassHouse Technologies, Inc. 
200 Crossing Boulevard
Framingham, MA 01702
orville.lantto AT glasshouse DOT com 
www.glasshouse.com 
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Mark Stapleton
Sent: Monday, December 11, 2006 2:08 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Survey Question for Virtual Tape Users: What
Vendors are you using for Virtual Tape?

From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Roger Deschner
>I keep hearing it said, that if you're going to buy a great big disk
>array for TSM, that it works better if you let TSM know it has disks
>(DEVCLASS=FILE), than if you lie and try to tell it they are virtual
>tapes.

The problem with this being, of course, that you get no compression of
data--the big advantage of VTL and the purpose of the VTL layer.

--
Mark Stapleton (mark.s AT evolvingsol DOT com)
Senior TSM consultant