Re: Reclaimation performance

     I can't resist... Well  you are using DLT tapes !

     20 hours is rather long!

     A few possibilities...
     1) was a data base backup running at the same time ?
     2) was a client,  whose data was on the tape being reclaimed,
     connected to the server during reclamation?
     3) any other process running OR heavy client load during this ?
     OR
     4) was there a high quantity of files in the remaining valid data on
     the source tape?

     all the above would drive adsm internal lock processing through the
     roof!

     example... a novell client wanted to speed their incremental backup.
     The adsm server scheduled activity for that node was a command:
     nightly.ncf that was basically
     load dsmc incremental data1:
     load dsmc incremental data2:
     load dsmc incremental data3:
     ...
     load dsmc incremental datan:
     the last of their tasks would end 15 hours later... by changing their
     scheduled activity to simply just a "incremental" the task finished in
     under 9 hours which tells me that 6 hours (total) had been spent
     fighting over adsm data base locks.  Compare it to kids and automobile
     trips !   One child in the back seat going "are we there yet" isn't
     really very bad but with 6 or 7! (the trip lasts a lifetime or maybe
     longer than a lifetime 'cause ya just want to die about half way
     there)

     On a Unix box there was a file system (and really only 1 big
     directory) with 1/2 million files which were (on the average) about 60
     bytes each.  Yes, the fully qualified directory path and file name was
     more bytes than actual data in the file (sigh).
     Yes, it can take HOURS to back up 50 MB

     So reclamation is no different... adsm  has to keep track the data and
     that equates to adsm db updates (inserts/deletes) and if the box is
     busy, has a slow processor, not much memory, or is just dealing with a
     ba-gillion files, it ain't gonna be fast.

     I've exceeded my 1 screen of reply so I'll shut up now...
     later,
           Dwight



______________________________ Reply Separator _________________________________
Subject: Re: Reclaimation performance
Author:  Mauro.TINELLI (Mauro.TINELLI AT ST DOT COM) at unix,mime
Date:    1/13/99 7:24 AM


Guy,

have a look at the Packet Utilization. Some tapes/media have a high
Packet Reclamation whilst maintaining a high Utilization ... I had/have
performance of 20 hours reclamation for single tape! I thought/hoped they
were getting better with the new release, but apparently they are still
bad.

Ciao Mauro


> To:         I1017261@IBMMAIL   IBMMAIL -I1017261 *ibmmail.I1017261
> Dear All,
>
>  Auto reclaimation started on my NT ADSM server yesterday at 13:30 (for
one
> tape) and it's still running 7 hours later.
> Server level 3.1.2.0
>
> Tape was DLT 4000: 96.2% avaiable for reclaimation.
>
> Does anyone have any ideas.
>
> I cancelled it and ran MOVE DATA which completed 3Gb in just over and
hour.
>
> Something must be wrong with reclaimation - I guess.
>
> Thanks   Guy.