ADSM-L

Re: direct attached disk (DAS) at a tape library?

2004-09-29 08:47:26
Subject: Re: direct attached disk (DAS) at a tape library?
From: Bill Smoldt <smoldt AT STORSOL DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Wed, 29 Sep 2004 06:49:09 -0600
Sal,

No, not too simplistic.  The environment you seek is quite feasible using
file devclass volumes and built-in TSM features.  What isn't feasible today
is using this as the primary means to move all IT data offsite for disaster
recovery, unless you don't have a lot of data or you have free bandwidth.

It's simply a matter of speed of the communication link and cost.  While you
can move a file hundreds of miles in seconds, you can't move 500GB of
changed data hundreds of miles in seconds, minutes, or hours each day for a
reasonable price with current technology.  If the communications costs were
free, we'd all do this.

If you have a very small amount of changed data each day, this may be
feasible for you.

Bill Smoldt
STORServer, Inc.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Sal
Mangiapane
Sent: Tuesday, September 28, 2004 7:11 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: direct attached disk (DAS) at a tape library?

Johnson, Milton wrote:
>  I am not quite sure what you meant by "with TSM you can use disk only
> for backups instead of onsite tape".  I do not see any reason why you
> can not use FILE device types for both primary and copypool stg pools.
> Of course if you actually want to move a copy of the data offsite, then
> you would need some type of removable media such as tape.

With data on disk a simple copy can move it hundreds of miles in seconds
or minutes.  Can't a FILE device pool be used to recover data in an
emergency?

Am I making this too simplistic?


Thanks,

Sal