How semi-live reformatVOB works

The semi-live reformatVOB process works by performing the reformatvob functionality in the background to minimize the amount of time the VOB is locked, or unavailable for users to perform their normal tasks.

The semi-live reformatVOB process allows reformatting VOBs up to, or at the schema 81.

To allow for this new functionality, a new database schema version is introduced, specifically to support the semi-live reformatVOB process. When the semi-live reformatVOB process is started, the existing database is upgraded to pick up the new database features. Schema 54 databases are silently upgraded to schema 55, and schema 80 databases up to 81. This upgrade only adds new tables, so the existing data is not modified and the schema upgrade happens in a few seconds.

The semi-live reformatVOB process works by copying the existing VOB db directory to a temporary copy, and that copied directory is reformatted using the existing dump and load utilities in the background. Once that copy is made, the new database schemas are used to track the transactions that occurred in the existing VOB database that is updated in the new semi-live reformatVOB database when the reformatvob dump and load are completed. Once the administrator determines that the semi-live reformatVOB process is completed, the new semi-live reformatVOB database is put in place.

The semi-live reformatVOB process has two stages:

  1. Initiating the semi-live reformatVOB process
  2. Completing the semi-live reformatVOB process

At any time during this process, use the command cleartool reformatvob -semilive -status <vob_stg_path> to query on the current status. While the semi-live reformatVOB process is in the initiating phase, there is currently no way to determine the progress of the reformatvob dump and load status. Once the dump and load processes are completed, a new process, the db_replay_server is queried to determine how many transactions need a replay.