Information on reformatting using the semilive option

Semi-live reformatVOB (SLRV) allows customers to upgrade the VOB database to the newer schema versions without all the required downtime required by the standard DevOps Code ClearCase® reformatvob functionality.

Modifying the ClearCase database schema takes a long time per VOB due to the reformatvob process, which executes two processes:

  1. The db_dumper reads from the current schema and outputs data into a few text files.
  2. The db_loader reads those text files and writes data into the new schema.

At the end of that process, directories are switched around and the new database with a new schema is available for use.

The reformatvob process takes a considerable amount of time for the large databases. During this time frame, the VOB is not usable as the VOB is locked. So, no write transactions occur. The administrators reformat each VOB at a time to reduce the downtime. However, in the UCM environments, a single VOB is unavailable (This means all the UCM operations are unavailable).

The semi-live reformatVOB process allows customers to easily upgrade to the newer schema versions.