23.9 Replacing a VOB or View Server Host

When you locate your VOB or view storage on a NAS device, you can easily designate a different ClearCase host of the same architecture to run the VOB or view server processes that manage access to the VOB or view without actually moving the VOB or view storage.

Replacing a VOB Server Host

The following procedure replaces the UNIX VOB server host ccvobsvr3 for the VOB /vobs/libpub with a different host of the same architecture, ccvobsvr1. The procedure locks the VOB, removes the old tag and registration, and then creates a new registration and tag specifying the replacement host and the existing storage.

1. Deactivate the VOB. Issue this command on each host where the VOB is currently active:

cleartool umount /vobs/libpub

NOTE: It may not be practical to unmount the VOB from all hosts. In this case, the VOB lock to be applied in Step #3 ought to prevent unintended VOB access.

2. (If applicable) Disable VOB snapshots on the current host. If VOB database snapshots are enabled for the VOB, disable them with the command:

vob_snapshot_setup rmparam /vobs/libpub

3. Lock the VOB. Do this as the root user or VOB owner.

# cleartool lock vob:/vobs/libpub
Locked versioned object base "/vobs/libpub".

4. Remove the VOB-tag and unregister the VOB.

# cleartool rmtag -vob -all /vobs/libpub
# cleartool unregister -vob /net/nasdevice/vobstg/libpub.vbs

5. Terminate the VOB's server processes on the current host. Search the process table for the vob_server and vobrpc_server processes that service the old VOB. Use ps -ax or ps -ef and search for libpub.vbs. Use kill(1) to terminate any such processes.

6. Register the VOB and create a new VOB-tag. You can use the ClearCase Administration Console or the following commands. (In this example, the VOB-tag is public, so the tag registry password is required.)

cleartool register -vob -host ccvobsvr1 -hpath /net/nasdevice/vobstg/libpub.vbs \
-gpath /net/nasdevice/vobstg/libpub.vbs /net/nasdevice/vobstg/libpub.vbs
cleartool mktag -vob -replace -host ccvobsvr1 -tag /vobs/libpub \
-hpath /net/nasdevice/vobstg/libpub.vbs -gpath /net/nasdevice/vobstg/libpub.vbs \
/net/nasdevice/vobstg/libpub.vbs
Vob tag registry password: <enter password>

7. Reactivate the VOB. On all client hosts:

cleartool umount /vobs/libpub (if not already done)
cleartool mount /vobs/libpub

8. Unlock the VOB. Do this as the root user or VOB owner.

# cleartool unlock vob:/vobs/libpub
Unlocked versioned object base "/vobs/libpub".

9. (If applicable) Enable VOB snapshots on the new host. If you want to enable VOB database snapshots on the new VOB host, do so with vob_snapshot_setup modparam, supplying the appropriate parameters.

Replacing a View Server Host

The process for replacing a view server host is similar. The following procedure replaces the UNIX view server host for dynamic view V4.1_Int. It stops the view, removes the old view-tag and registration (object), then creates a new registration and tag specifying the replacement host and the existing storage.

1. Log on to the view's server host. Log in as the view's owner.

2. Deactivate the view. Use the cleartool endview command to stop the view and terminate the view's view_server process:

cleartool endview -server V4.1_Int

3. Delete the existing view-tag. You can use the ClearCase Administration Console or the following command.

cleartool rmtag -view V4.1_Int

4. Create a new view object and tag specifying a new view server host and the existing storage. You can use the ClearCase Administration Console or the following commands.

cleartool register -view -replace -host ccviewsvr1 \
-hpath /net/nasdevice/viewstg/v4.1_int.vws \
-gpath /net/nasdevice/viewstg/v4.1_int.vws /net/nasdevice/viewstg/v4.1_int.vws
cleartool mktag -view -tag V4.1_Int -host ccviewsvr1 \
-gpath /net/nasdevice/viewstg/v4.1_int.vws \
-hpath /net/nasdevice/viewstg/v4.1_int.vws /net/nasdevice/viewstg/v4.1_int.vws

5. Reactivate the view on the replacement view server host.

cleartool startview V4.1_Int

6. Update corresponding VOB databases. The view's old location is still recorded in the databases of all VOBs that the view accessed with checkout and/or clearmake. For each such VOB, update the view-location information by checking out one of the VOB's elements in that view. (You can cancel the checkout with cleartool uncheckout immediately if you want.)