TSM will mount and start as many sessions as possible, and the rest will
be in 'wait media' state until the tape they need (or a tape drive)
becomes available. Given your scenarion, you may have one session
reading tape and the other four waiting for access to the same tape.
When the first session has retrieved ALL the files it needs from the
first tape, it will go to the second (if not in use) and the session
that has been waiting the longest will now get access to that first
tape.
Tom Kauffman
NIBCO, Inc
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Troy Frank
Sent: Friday, August 18, 2006 12:23 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: server restore behavior
This is more of a curiosity question than a problem. In a
multiple-client restore scenario where you start up say 5 restores at
once from different nodes (with 4 tape drives, and resourceutilization
set to 4 on nodes), how does the server process the request?
Technically, data from all 5 nodes are probably on a lot of the same
tapes. Does it....
A) mount each tape exactly once, getting all data for all running
restores off that tape before unmounting.
B) Process the restores relatively serially for each node, giving each
all 4 drives until completed. Unmounting/remounting the same tapes
multiple times.
C) Only give each node 1 tape drive to work with, which will
effectively ellicit behavior very similiar to option B.
Or does it do something different than any of these?
Confidentiality Notice follows:
The information in this message (and the documents attached to it, if
any)
is confidential and may be legally privileged. It is intended solely for
the addressee. Access to this message by anyone else is unauthorized. If
you are not the intended recipient, any disclosure, copying,
distribution
or any action taken, or omitted to be taken in reliance on it is
prohibited and may be unlawful. If you have received this message in
error, please delete all electronic copies of this message (and the
documents attached to it, if any), destroy any hard copies you may have
created and notify me immediately by replying to this email. Thank you.
CONFIDENTIALITY NOTICE: This email and any attachments are for the
exclusive and confidential use of the intended recipient. If you are not
the intended recipient, please do not read, distribute or take action in
reliance upon this message. If you have received this in error, please
notify us immediately by return email and promptly delete this message
and its attachments from your computer system. We do not waive
attorney-client or work product privilege by the transmission of this
message.
|
