ADSM-L

Re: ANR8447E .. Mount failed even though several drives in "idle" status

2005-04-05 09:10:35
Subject: Re: ANR8447E .. Mount failed even though several drives in "idle" status
From: Richard Sims <rbs AT BU DOT EDU>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 5 Apr 2005 09:09:59 -0400
Hi, David -

That QuickFacts entry harks back to sharing via physical library
partitioning. I'll update that to be more in tune with current
regimens.

Looking through various TSM manuals and redbooks over time shows them
generally recommending not using MOUNTLimit=DRIVES; rather, the number
of drives should be explicitly coded. (One reference is redbook "Using
Tivoli Storage Manager in a SAN Environment".) From a systems
programmer perspective I wholeheartedly agree with explicit
specification, given the number of times I've seen technologies get
numbers wrong in discovery processes.

I'm not sure what you mean by "locally allocated"...which may imply
that you have more going on there than I first thought in terms of
library management. Here's a quote from the Admin Guide which may
relate to a more complex environment:

"For environments in which devices are shared across storage
applications, the MOUNTRETENTION setting should be carefully
considered. This parameter determines how long an idle volume remains
in a drive. Because some media managers will not dismount an allocated
drive to satisfy pending requests, you might need to tune this
parameter to satisfy competing mount requests while maintaining optimal
system performance."

   Richard Sims

On Apr 5, 2005, at 8:19 AM, David Nicholson wrote:

Thanks for the reply Rich...

I am curious about the following from Quick Facts

        In a library shared by multiple servers, you need to define the
number
        of drives actually allocated to each server; otherwise, if you
let
        DRIVES prevail, each server may think it should have access to
all
the
        drives in the library.

This is a library sharing environment and devclass's on both servers
are
set to MOUNTL=DRIVES.   This is the way I have had it set up for a
couple
years and I have not noticed it being a problem before.  Actually, I
thought it was recommended to use MOUNTL=DRIVES...but Quick Facts says
otherwise.  Far be it from me to question a quick
fact........buuuuttttt
it seems lowering the MOUNTL to something less than "drives" would
somewhat defeat the idea of library sharing.  Does a pre-empt of
MOUNTRETENTION only apply if the "idle" drive was locally allocated?

Thanks in advance

David R. Nicholson





Richard Sims <rbs AT BU DOT EDU>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
04/05/2005 07:39 AM
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        Re: ANR8447E .. Mount failed even though
several drives in "idle" status


Mount retention is pre-empted to gain access to a drive, providing that
no process or session is engaged to use the drive and media.
See that msg in http://people.bu.edu/rbs/ADSM.QuickFacts for reasons we
have experienced. Check your Devclass MOUNTLimit as the most common
cause, plus your Activity Log for accompanying messages.

   Richard Sims

On Apr 5, 2005, at 7:23 AM, David Nicholson wrote:

All,

TSM Server 5.2.4.0  (AIX 5.3)
3494 library w/ (15) 3590E

        Suddenly (I think) I am getting a LOT of ANR8447E messages.
A "q
mount" shows several drives in an "idle" state. My mount retention is
set
to '3'.  I thought that the mount retention would be preempted if
there
was a need to mount  a new tape. Can someone confirm or deny this for
me?
I am finding if I manually "dismount vol xxxxxx" the problem goes away
for
a bit until I get several "idle" drives again.

<Prev in Thread] Current Thread [Next in Thread>