Even using the dsmmode -t=p option when doing a selective backup, changes
the atime of the file.
I've just tested it. Using "istat filename", one can see
the access time for that file. The dsmmode -t=p option does not preserve
the access time as they claim. So this is a huge problem for me.
We can only migrate files on our /R3_data filesystem if the files have
not been accessed for at least 30 days. Any other ideas as on how
to solve this problem?
Gerrit van Zyl writes:
> Reinhard,
>
> I had a look:
>
> 1. No errors in the AIX errorlog.
> 2. No, I do not catch HSM error messages with the ERRORPROG
option. How do you use this?
What I am doing is: In dsm.sys:
ERRORPROG
/var/adsm/errorprog
/var/adsm/errorprog is a shell script essentially containing one line:
mail -s "Mail from HSM" backup
This sends the HSM error message to "backup" (which is me). Don't forget
to make that script executable.
> 3. Dsmmonitord is running.
> 4. This is a huge filesystem, and no, it is impossible
that all of the files have been accessed.
You are backing them up, don't you? (See below.)
> 5. Dsmreconcile gives the following:
> f03n13sw / # dsmreconcile -c /R3_data
> ADSTAR Distributed Storage Manager
> space management Interface - Version 3, Release 1, Level 0.7
> (C) Copyright IBM Corporation, 1990, 1999. All Rights Reserved.
>
>
> Reconciling '/R3_data' file system:
> Querying the ADSM server for a list of backed up
files...
> Received
705752 entries
Boy, this IS huge. There seem to be a lot of small files within the
filesystem. Don't forget that small files (4KB or less) will not be
migrated! Does this explain your problem?
> Now traversing the file system...
> Writing the new migration candidates list...
> Note:
unable to find any candidates in the file system.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Obviously, this is the problem. I can only guess about the reason.
All
possible candidates smaller than 4KB? To repeat myself: I would set
AUTOMIGNOUSE to 0. APAR IX89650 might apply to you (text appended below).
> ANS9250I File system '/R3_data' reconciliation completed.
>
> 6. I am able to manually migrate files.
> 7. Set the quota (e.g. "dsmmigfs update /R3_data -Quota=1024G"
> you do allow 1 TB from this filesystem
to be migrated, don't you?)
> What do you mean with this?
The quota specifies the amount of data that may be migrated. You did
not
specify a quota, I would definitely do so. (The default is quite small.)
APAR IX89650:
APAR NUMBER: IX89650
RESOLVED AS: DOCUMENTATION ERROR
ABSTRACT:
IX89650: UNABLE TO SPACE MANAGE FILES BASED ON AUTOMIGNONUSE=1
AS ADSM
INCREMENTAL AND SELECTIVE BACKUPS ALTER THE FILES ATIME VALUE.
ORIGINATING DETAILS:
The ADSM backup/archive client alters files atime value during
selective or incremental backups. This results in HSM being
unable to properly migrate files based on the automignonuse
value set in the mgmtclass. This was tested on AIX 4.2.1 with
the 3.1.0.6 client code.
LOCAL FIX AS REPORTED BY ORIGINATOR:
Run the selective or incremental backup as a command parameter
of the dsmmode -t=p command. Example:
'dsmmode -t=p dsmc i'
RESPONDER SUMMARY:
The BA client in ADSM v2 preserved the atime
of files for backup and restore. Preserving the atime
of files for reading has been disabled 11/97. Reason:
when preserving the atime (using syscall utime(), the ctime
of the file was indirectly updated. HSM uses ctime as part of
the key for the premigration database. The ba client uses the
ctime (besides other file attributes) to compare the state
of files. Unfortunately, this modification has never been
reflected in the documentation, since it limits the use
of the
'non-usage' option of the ADSM HSM client.
RESPONDER CONCLUSION:
Trying to preserve the time stamp of a file,
using syscall utime(), indirectly changes the ctime time stamp,
which leads to undesired side affects.
--
Reinhard Mersch
Westfaelische Wilhelms-Universitaet
Zentrum fuer Informationsverarbeitung - ehemals Universitaetsrechenzentrum
Roentgenstrasse 9-13, D-48149 Muenster, Germany
Tel: +49(251)83-31583
E-Mail: mersch AT uni-muenster DOT de
Fax: +49(251)83-31653
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