Good question, but I wouldn't see the need to only use certain drives for
recoveries.  Dedicated in respect to this has more of a dynamic meaning.
The backups will only use up to the number of drives stated in the Storage
unit config.  Restores can use as many as needed.  

The ideal behind a dedicated restore drive only really matters during a
backup window.  When you are full blown using all of the drives, say in the
middle of the night, trying a restore without having a dedicated drive you
would have to wait for the backups to stop or for the restore to work
through the queue.  (This is an expensive option for impatience or time
critical restores).  

During a the timeframe when no or a few backups are running I don't see how
it matters what drives are used.  They are not dedicated in the sense of the
same drive is used every time.

Hope this helps,
James Dean
Enterprise Backup Systems, Manager
USinternetworking Inc.


-----Original Message-----
From: Ravi Channavajhala [mailto:ravi.channavajhala AT csfb DOT com]
Sent: Wednesday, October 04, 2000 6:32 PM
To: Dean, James
Cc: 'John_Wang AT enron DOT net'; veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Reserving one drive in robot for reads


Interesting, but what's not clear is does it pick the dedicated
drives always for restoring unless of course, you initiate several
recoveries at once?

In other words, how can you prevent non dedicated drives from being
used ever for 'recoveries' and have every recovery done from
dedicate drives only.  Thanks.

-ravi

On Wed, 4 Oct 2000, Dean, James wrote:

jimmy>In your storage unit configuration, change the number of drives to one
less
jimmy>then the actual number of drives known to the Master/Media.
jimmy>
jimmy>This will guarantee that only X number of drives are used for backups
and
jimmy>the full amount of drives known to the Master/Media will be used for
jimmy>restores.
jimmy>
jimmy>Ex. for 2 restore drives in a 16 drive TLU
jimmy>
jimmy>1 Master/Media
jimmy>1 TLU w/ 16 drives
jimmy>
jimmy>Storage unit setup:  Number of drives 14
jimmy>
jimmy>This gives you 2 dedicated and 14 possible restore drives, but only 14
jimmy>backup drives.
jimmy>
jimmy>James Dean
jimmy>Enterprise Backup Systems, Manager
jimmy>USinternetworking Inc.
jimmy>
jimmy>-----Original Message-----
jimmy>From: John_Wang AT enron DOT net [mailto:John_Wang AT enron DOT net]
jimmy>Sent: Wednesday, October 04, 2000 2:49 PM
jimmy>To: veritas-bu AT mailman.eng.auburn DOT edu
jimmy>Subject: [Veritas-bu] Reserving one drive in robot for reads
jimmy>
jimmy>
jimmy>
jimmy>
jimmy>Hello
jimmy>
jimmy>Is it possible to rotate through the drives and always keep one
reserved for
jimmy>restores?   How?
jimmy>
jimmy>Regards,
jimmy>John I Wang
jimmy>Sr. Systems Engineer
jimmy>Steverson Information Professionals
jimmy>
jimmy>---
jimmy>Enron Broadband Services
jimmy>3 Allen Center, Room 337C
jimmy>PH (713) 345-6238
jimmy>
jimmy>
jimmy>_______________________________________________
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