Does anyone know if TSM still puts directories in the mgmtc with the
longest retention period?  On one of my machines, that belongs to a special
group of machines with all sorts of special handling.  I've used DIRMC to
ensure the directory of some desktop doesn't get treated in the same way.


At 01:25 PM 3/19/2005 -0800, you wrote:

Paul,
Using a separate pool for directories is something that many have been
doing for a long time and just kept doing even after IBM implemented the
new directory restore method (restore order processing).  If you look at a
directory as a small file then you can see why keeping it in a separate
pool so that you can keep that data on disk might help.  This is one
reason why we have not yet stopped using the DIRMC.  With that being said
more and more of my customers are implementing file device classes or
VTL's which keep most of the primary data on disk.  As a result I no
longer see the need for separating out the directories to another disk
location.

About a year ago many of my larger customers would complain about how long
the DIRMC disk pools would take to backup.  In working with support we
found that this was a WAD feature. I think the issue was (can't remember
for sure) that each file in a disk pool is evaluated on every backup where
sequential access pools are evaluated differently.  As a result we started
taking our DIRMC pools and giving them a small pool built with a file
device class definition.  We made sure the data migrated from disk to file
device class each day and as a result the storage pool copy problem went away.

Now the fact that we are using file device classes as described above is
why I am concerned about the issue that was mentioned in this thread about
the larger default block size.

All of these issues together lead me to believe that DIRMC pools are no
longer as necessary as they used to be.

Kyle


Paul Fielding <paul AT FIELDING DOT CA> wrote:
Hi Richard,

I took a look through the Quickfacts (something I should have done long
ago). It does indeed suggest that surrogate directories are created and the
real directories are restored as they are hit.

Has anyone really observed this to be genuinely true? I have in the past
observed the double-tape-mount theory, and though I understand it is
supposedly fixed, I haven't heard anyone say "I have seen it, I know it
works, you no longer need to keep a dirmc diskpool".

Of course, if it is indeed working as designed now, it doesn't resolve the
other dirmc issues currently being discussed in this thread.

Is there anyone on the list who has in recent history decided to ditch using
a dirmc diskpool altogether and done so with success on the restore side?

regards,

Paul

----- Original Message -----
From: "Richard Sims"
To:
Sent: Saturday, March 19, 2005 4:44 AM
Subject: Re: [ADSM-L] DIRMC - Are copypool reclamation performance issues
resolved or not.


> Paul -
>
> This generally falls under the TSM term Restore Order processing. We've
> discussed it on the List before. I have an entry on it in ADSM
> QuickFacts which you can refer to as a preliminary to further pursuit
> in IBM doc.
>
> Richard Sims http://people.bu.edu/rbs
>
> On Mar 19, 2005, at 3:06 AM, Paul Fielding wrote:
>
>> I'd be interested in more discussion on this point. My original
>> understanding was actually a bit different that that. The impression
>> I had
>> was that originally directory tree structures were restored before any
>> files
>> happened, period. Following that, files would be restored. Net result
>> -
>> tapes might get mounted twice.
>>
>> Is my understanding incorrect? (could well be). If this behavior has
>> indeed
>> been fixed so that directories are restored as they are hit on the tape
>> (with a pre-created non-ACLed directory being created first) then it
>> would
>> indeed make sense that a DIRMC pool is no longer needed.
>>
>> Is there any documentation on this somewhere I can reference?
>



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Fred Johanson
ITSM Administrator
University of Chicago
773-702-8464