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-o snapshot [ -F ] | resync
db2ed_vmsnap -D DB2DATABASE -f SNAPPLAN
-o reverse_resync_begin | reverse_resync_commit | reverse_resync_abort
lslpp -L VRTSdb2ed
The db2ed_vmsnap command can also resynchronize the split images back to the current database image or resynchronize the original volume from the data in the snapshot. You can use the snapshot image on either the same host as the database or on a secondary host provided storage is shared by the two hosts. The file containing the snapplan specifies the snapshot scenarios (such as online_snapshot, online_mirror, or offline).
The snapshot image created by db2ed_vmsnap is a frozen image of the specified DB2 database.
When the SNAPSHOT_MODE parameter is set to online_snapshot or online_mirror in the snapplan, db2ed_vmsnap puts the database into WRITE SUSPEND mode when the snapshot is created. After db2ed_vmsnap finishes creating the snapshot, it takes the database out of WRITE SUSPEND mode. For online_snapshot, the online redo log must be included in the snapshot if a clone database is to be started. If SNAPSHOT_MODE is set to offline, online redo logs are required and the primary database needs to be down when the snapshot is created. The database will not be placed into WRITE SUSPEND mode.
The snapshot functionality is useful if you want to use a secondary host for backup or a clone database for off-host processing work (such as decision-support analysis and report-generation operations, for example).
The -F option can be used after a snapshot operation has failed and the problem was fixed without using Veritas Storage Foundation for DB2 commands. (That is, the volumes were synchronized without using Veritas Storage Foundation for DB2 commands.) In this situation, the status of the snapplan will appear as unavailable for creating a snapshot. The -F option ignores the unavailable status, checks for the availability of volumes, and creates the snapshot after the volumes pass the availability check.
After the snapshot is created, db2ed_vmsnap returns values you will need to run db2ed_vmclonedb. These values include the snapshot disk group, the snapplan name, and the VxDBA repository volume (for a two-host configuration). Make a note of these values so you have them when running db2ed_vmclonedb.
After aborting reverse resynchronization, you can run db2ed_vmclonedb -o restartdb to restart the clone database if it was previously brought up. You can also re-run db2ed_vmsnap -o reverse_resync_begin if the SNAPPLAN_MODE is set to online_snapshot and a clone database was brought up.
Caution: Upon completion of reverse resynchronization, the content of the original database is discarded. Storage Checkpoints taken on either the original database or the clone database after the snapshot was created are discarded. Storage Checkpoints taken before the snapshot was created are preserved. The db2ed_vmsnap -o reverse_resync_commit command cannot be undone and should be used with extreme caution.
Before the DB2 instance owner can use this command, however, the system administrator needs to prepare Veritas Volume Manager persistent FastResync on the existing database volumes and assign disks for snapshot volumes.
The db2ed_vmsnap command runs without interaction from the user.
It is recommended that you create a local working directory to store your snapplans in.
After a snapplan is created, run the db2ed_vmchecksnap utility to validate it. If a snapplan is modified or changed, you must revalidate it by running db2ed_vmchecksnap.
Veritas Storage Foundation for DB2 Administrator's Guide
Last updated: 15 Jan 2005
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