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Monday, June 30, 2014

Restoring a database to a point-in-time -- volume history file unavailable



Restoring a database to a point-in-time -- volume history file unavailable

If the volume history file is unavailable, you can use one or more
DSMSERV RESTORE DB commands to restore the database to a specific point
in time. A device configuration file with the applicable device
information must also be available, or you must manually create one.



For example, to load a full backup and one or more incremental backups,
issue a DSMSERV RESTORE DB command for the full backup and an additional
DSMSERV RESTORE DB command for each incremental backup. When you use
multiple DSMSERV RESTORE DB commands, specify COMMIT=NO for each command
except the last one. For the last command, specify COMMIT=YES. The
database remains in an inconsistent and unusable state until you issue a
DSMSERV RESTORE DB command with a COMMIT=YES.

To manually create a device configuration file with the applicable
device information (library, drive, and device class definitions) see
the Administrator's Guide).

Full and incremental database backups or snapshot database backups can
be used to restore a database to a point in time.

To restore the database using snapshot backup volumes, you must:

1. Specify all the volume names for the same snapshot backup series
2. List the volumes in the sequence in which the backup was written
3. Specify COMMIT=YES

Note:
      1. If you issue a DSMSERV RESTORE DB command with COMMIT=NO, and
         you decide not to load another incremental backup, reissue the
         last DSMSERV RESTORE DB command with COMMIT=YES.
      2. If you issue a DSMSERV RESTORE DB command with COMMIT=YES, and
         you decide to load an additional incremental backup, reissue
         all the DSMSERV RESTORE DB commands in order with COMMIT=NO on
         each. Then, enter any additional DSMSERV RESTORE DB commands,
         with COMMIT=YES on the last one.



Syntax

>>-DSMSERV RESTORE DB--DEVclass--=--device_class_name----------->

                     .-,-----------.     
                     V             |     
>--VOLumenames--=--+--volume_name-+-+------------------------>
                   '-FILE:--file_name-'  

   .-COMMIT--=--No------.  
>--+-------------------+-------------------------------------><
   '-COMMIT--=--+No--+'  
                '-Yes-'    




Parameters

DEVclass (Required)
   Specifies the name of the sequential access device class to use. The
   device class must be defined in a device configuration file. If a
   device configuration file is not available, you can manually create
   one (see the Administrator's Guide).

   Note:
         1. You cannot use a device class with a device type of NAS.
         2. A restore database operation fails if the source for the
            restore is a FILE library. A FILE library is created if the
            device class specifies SHARED=YES.

VOLumenames (Required)
   Specifies the backup volumes to use to restore the database. Possible
   values are:

   volume_name
      Specifies the names of the volumes. To specify multiple volumes,
      separate the names with commas and without intervening spaces.
      List the volumes in the order in which they were written.

   FILE:file_name
      Specifies the name of a file that contains a list of the volumes.
      Enter the volumes in the order in which they were written with
      each name on a separate line.

COMMIT
   Specifies whether this is the last restore command needed to restore
   the database. This parameter is optional. The default value is NO.
   Possible values are:

   No
      Specifies that you will issue one or more additional DSMSERV
      RESTORE DB commands.

   Yes
      Specifies that this is the last restore command to restore the
      database.



Examples

Task 1

Restore the database to the time of its most recent incremental backup.
The volume history file is not available. Tape volumes FULL1, FULL2,
INCR1, and INCR2 contain the database backup series.

Commands

dsmserv restore db devclass=tape volumenames=full1,full2 commit=no



dsmserv restore db devclass=tape volumenames=incr1 commit=no



dsmserv restore db devclass=tape volumenames=incr2 commit=yes

Task 2

Restore a database to the time of its most recent snapshot backup. The
volume history file is not available. Tape volumes TAPE01 and TAPE02 are
snapshot volume names in a volume sequence that spans two tapes.

Command

dsmserv restore db devclass=8MM volumenames=tape01,tape01 commit=yes