Creating a VOB on Linux and UNIX

To create a VOB on Linux and UNIX, you use the cleartool mkvob command.

The mkvob command does the following:

  • Creates a VOB storage directory at the path you specify. The VOB storage directory contains database and a set of storage tools.
  • Creates a VOB tag with which the developers access the VOB.
  • Places entries in the network's VOB registry.
  • Starts a VOB server process on the VOB server host.

Note that, depending on the platform and DevOps Code ClearCase® product you use, not all command options are available.

Creating the VOB with the mkvob command does not automatically mount the VOB. To mount the VOB, use the mount command.

To create a VOB using the mkvob command, do the following:

  • In a command window, enter this command. The options shown in this command are available on all platforms and for all DevOps Code ClearCase products.

    cleartool mkvob -tag vob-tag -comment comment -tcomment tag-comment -stgloc vob-stgloc-name

Let's examine what happens when you issue the command as shown with these parameters.

  • mkvob creates a VOB. The command also creates a VOB root directory and a lost+found directory.
    • VOB root directory. A mkdir command is implicitly run to create the VOB root directory element in the new VOB. Activating a VOB makes its root directory accessible at the path specified by the VOB tag.
    • lost+found directory. In ClearCase, mkvob also creates a special directory element, lost+found, as a subdirectory of the VOB root directory. In this directory are placed elements that are no longer entered in any versioned directory.
  • -tag vob-tag specifies the name and path for the VOB.
  • -comment comment specifies a comment for all event records created by the command. The comment string must be a single line; typically, you must enter it between single or double quotes.
  • -tcomment tag-comment adds a comment to the VOB tag's entry in the vob_tag registry file.
  • -stgloc vob-stgloc-name lets you specify the name and path of the storage server.

Unless you use the -public option, the VOBs you create are private VOBs.

The preceding is just a sample of available options to create a VOB with the mkvob command.

Try it!

Type this command at the system prompt of a terminal window:

cleartool mkvob -tag /tmp/your-username_case_tutorial -tcomment "tutorial exercise VOB" -comment "initial creation of the tutorial VOB" ~/your-username_clearcase_tutorial.vbs

For example: cleartool mkvob -tag /tmp/jsmith_clearcase_tutorial -tcomment "tutorial exercise VOB" -comment "initial creation of the tutorial VOB" ~/jsmith_clearcase_tutorial.vbs

When successful, the system response is similar to the following:


Created versioned object base.
Host-local path: goose:/export/home/fhembert/fhembert_clearcase_tutorial.vbs
Global path: /net/goose/export/home/fhembert_clearcase_tutorial.vbs 
VOB ownership:
    owner stellar.com/fhembert
    group stellar.com/user 
VOBs have special data backup considerations. For more information on how to
back up your VOB properly, see the documentation for administering ClearCase. 
If the backups aren't done properly, you are putting you data at risk!