Re: size of stub files changed after restoring an entire fil

Classification:
Prologue: From the desk of  Matt Anglin, ADSM Development
Epilogue:

Yes, this is normal.  When a file is migrated, we leave behind the "stub".  The
stub contains information we need to recall the file, plus some amount of user
data.  The amount of data we use is 511 bytes, and the amount of data we leave
in the file is the stub size minus the 511 bytes.  When you do a
dsmmigundelete, we simply put back enough data to recreate the stubs, with 0
bytes of user data (since you don't want us going out to tapes to recover the
rest of the stub).
When the file gets recalled, then migrated again, we once again have user data
that we can leave in the stub, so the stub size goes back to its original value.

Matt Anglin
ADSM Development



        owner-adsm-l @ VM.MARIST.EDU
        02-05-97 08:54 AM
Please respond to ADSM-L AT VM.MARIST DOT EDU@internet


To: ADSM-L @ VM.MARIST.EDU@internet
cc:
Subject: size of stub files changed after restoring an entire file sy

I am running ADSM HSM.  After losing a disk I had to do a complete restore of
a filesystem.  I followed the instructions in the HSM manual on restoring an
entire file system, and this is what I did:

        recreate filesystem
        dsmc restore -dirsonly /monitor
        dsmmigundelete /monitor
        dsmc restore -replace=no -subdir=yes /monitor

After the file system was restored I did a 'dsmls' and saw that the stub files
are now 511K instead of what it was, 4095K.  I have no problem restrieving
the migrated files.  In fact, after a file is retrieved and then migrated again
the stub file returns to 4095K.  Everything is in order but I am just
wondering why the size of the stub files changed.  Is this normal?

Server: AIX 4.1.4   ADSM 2.1.0.10
Client: AIX 4.1.4   ADSM 2.1.0.6

$ dsmls
ADSTAR Distributed Storage Manager
space management Interface - Version 2, Release 1, Level 0.6
(C) Copyright IBM Corporation, 1990, 1996, All Rights Reserved.

   Actual  Resident  Resident  File   File
     Size      Size  Blk (KB)  State  Name

/monitor/sigcomm96/CLFsim/BR.runs/BR_SLN.new.trace:
   263118       511         4  m      9390A.hit
    48453       511         4  m      9390A.stack
    69429       511         4  m      9391A.stack
   313131       511         4  m      9392A.hit
    60718       511         4  m      9392A.stack
    25368       511         4  m      9393A.rem
    64813       511         4  m      9393A.stack
    17282      4095         4  m      9394A.rem
   276604       511         4  m      9395A.hit

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 Eliza Lau
 Eliza Lau
 Virginia Tech Computing Center                Internet : eliza.lau AT vt DOT 
edu
 Virginia Polytechnic Institute & State University
 1700 Pratt Drive
 Blacksburg VA 24060                            Voice   : (540) 231-9399
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