If V5.3 in fact only writes in larger blocks in the smaller directories may 
take up more space that required.

Still, that issue aside you should no longer need to have a DIRMC pool. At one 
time there was a feature (or call it a bug) where every directory had to be 
restored as it came up which would cause many more mounts of tape drives.  For 
some time now a restore create a directory (without ACL's) so that the restore 
can continue. Then when the directory itself is hit it will simply restore over 
top of the directory that was created.  This will ensure each tape is still 
only ready once.  True, directories are like small files and just like small 
files restoring from disk would be faster but the bug that used to exist has 
long since been fixed.

Further as people implement file device class storage pools and other disk only 
solutions like VTL's I don't see the need for seperating the directories into a 
seperate pool.

Kyle

"Rushforth, Tim" <TRushforth AT WINNIPEG DOT CA> wrote:
What in 5.3 warrants new consideration?

The reason we implemented DIRMC is so that when a user restores a file(s) there 
are not extra tape mounts to restore the directories We ran into this on 
multiple occasions, even when all files were on disk, tape mounts would occur 
because the directories were on tape.

Thanks,

Tim Rusforth
City of Winnipeg

-----Original Message-----
From: TSM_User [mailto:tsm_user AT YAHOO DOT COM]
Sent: Wed 3/16/2005 6:48 PM
To: ADSM-L AT VM.MARIST DOT EDU
Cc:
Subject: Re: DIRMC - Are copypool reclamation performance issues resolved or 
not.



It is fixed but the reason there have been suggestions to use a file type 
device class is because disk pools unline sequential pools are scanned from 
begining to end for every storage pool backup. I have had some customers that 
have millions of directories in their DIRMC pool. Even when none change they 
backup runs from hours on that pool. With a file type device class only the new 
volumes would be backed up resulting in a much faster backup. Now all that 
being said this new feature in V5.3 warrents new consideration. My new 
consideration is to stop using DIRMC pools as the reason they were created in 
the first place has also long been fixed.

Kyle

"Thorneycroft, Doug"
wrote:
OK, after spending a large portion of my day reviewing adsm-l post going back to
2000, I'm still not sure. Does anyone know if there is still a performance 
problem
running reclamation on a DIRMC random access disk pool?
I came across one post that said it was supposedly fixed, but recommended using
a file type diskpool to be safe.


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