Yes, only the tape drives are shared. There is still only one Robot Control
Host. For a DLT tape library all servers sharing the drives are running tldd
to communicate with the drives, but only the Robot Control Host is running the
tldcd process to control the robot.
The Robot Control Host is not the server that handles the requests for shared
drives (although it would be if it was also your VolDB host). Allocation of
the drives is handled by the Device Allocation Host (vmd/DA) which is always
the Volume Database Host. Information about your SSO environment can be
gathered using volmgr\bin\vmdareq. It can also be used to register/unregister
and reserve/release the drives.
how many drives a host has registered and how many are currently reserved
vmdareq -hostinfo -a
tells whether a drive is available and if not, who has reserved it
vmdareq -driveinfo
If you are using SSO, this is a MUST!
http://ftp.support.veritas.com/pub/support/Products/NetBackup_DataCenter/mediamgr_dc_adminguide_sso_233840.pdf
And for those of you new to the product, I would also highly recommend reading
the NetBackup Functional Description and Media Manager Functional Description
in the NetBackup Troubleshooting Guide.
- Scott
anthony.guzzi AT storability DOT com
Sent by: To: veritas-bu AT
mailman.eng.auburn DOT edu
veritas-bu-admin AT mailman DOT eng. cc:
auburn.edu Subject:
[Veritas-bu] Re: Does SSO Use SCSI Reserve/Release?
05/31/2001 01:50 PM
Curtis,
I'm sure you'll get a lot of responses on this, so consider my comments
just part of the chorus. If I understand SSO correctly, only the tape
drives are shared, not the robot. The robot is controlled by a single
server which handles all tape mounts/unmounts. In addition, this server
also coordinates access to the tape drives. It does this by running the
'vmd' process (on a Unix system) in 'device allocation' (DA) mode.
-- Tony Guzzi
Solutions Engineer, AssuredRestore team
Storability, Inc.
118 Turnpike Road
Southborough, MA 01772
www.storabilility.com
The Leading Provider of Automated Storage Assurance for the Enterprise
veritas-bu-request AT mailman.eng.auburn DOT edu
Sent by: veritas-bu-admin AT mailman.eng.auburn DOT edu
05/31/2001 01:06 PM
Please respond to veritas-bu
To: veritas-bu AT mailman.eng.auburn DOT edu
cc:
Subject: Does SSO Use SCSI Reserve/Release?
Message: 5
Date: Thu, 31 May 2001 09:55:36 -0700
To: veritas-bu AT mailman.eng.auburn DOT edu
From: "W. Curtis Preston" <curtis AT backupcentral DOT com>
Subject: [Veritas-bu] Does SSO Use SCSI Reserve/Release?
I'm getting conflicting information from a couple of different sources,
and
I KNOW that someone out there knows the real answer.
How does SSO (for NetBackup & BE if possible) managed contention for the
robot? It would seem that this could be done in one of two ways:
1. It uses the SCSI Reserve command when it starts to use the arm.
<...... text deleted. -AJG ......>
---
W. Curtis Preston
Principal Consultant for Storage Designs, your storage experts
Webmaster: http://www.backupcentral.com Phone: 760 631 7991
_______________________________________________
Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
|
