19.1 Backing Up a View

Backing up views is similar to backing up VOBs, but simpler:

• Users can create views under their home directories. In this case, whatever backup regimen you have in place to back up users' home directories picks up their view storage directories as well.

• Views do not have multiple storage pools. A dynamic view has a single private storage area, its .s subdirectory. If the view is on a UNIX host, this directory can be located on a remote computer. Otherwise it must be located on the host where the view_server runs. A snapshot view's files and directories reside in the snapshot view directory tree.

• It never makes sense to attempt a partial backup of a view storage directory (or, for a snapshot view, a view directory tree); all the data is important, because it's the only copy of one or more users' current work.

If you are backing up a snapshot view, you must back up both the view directory tree and the view storage directory. If the view storage directory is located outside the view's directory tree, you must be sure to back up both.

Use the following procedure to back up a view:

1. Determine the location of the view storage directory. Use the ClearCase Administration Console or run lsview to display view storage information. If your backup program runs over the network, you need the Global path. If your backup program runs locally, you need the View server access path:

cleartool lsview -long akp_vu
Tag: akp_vu
Global path: /net/neptune/home/akp/views/akp.vws
...
Region: dvt
...
View on host: neptune
View server access path: /home/akp/views/akp.vws
...

2. Ensure integrity and consistency of the backup. To keep the view inactive while it is backed up, warn ClearCase users not to use it during the backup, or use the chview command to prevent users from updating the view database.

cleartool chview -readonly akp_vu
Properties: readonly

This command does not prevent changes to the view's config spec. To keep the config spec from being changed during backup, rename the view storage directory before backing it up, and then stop the view_server with cleartool endview -server view-tag.

3. On Windows, stop ClearCase on the view host. Common Windows backup utilities do not back up files that are open for write. Because the view database files are typically held open for write while Rational ClearCase is running, your backup operation skips these files, unless you stop ClearCase before performing the backup. Unless your backup software is known to capture files open for write access, you must stop ClearCase on the view host before performing a backup. Use the ClearCase program in Control Panel to stop ClearCase on the view host. If you are backing up a snapshot view, ensure that no users are working with files in the view's directory tree.

4. On UNIX, determine whether the view has remote storage. You can use a standard ls(1) command:

cd /home/akp/views/akp.vws
ls -ld .s
... .s -> /net/ccsvr04/viewstore/akp.stg

A symbolic link indicates remote private storage area.

5. Enter the backup commands. For a snapshot view, back up the entire view directory tree. For a dynamic view or for a snapshot view whose view storage directory is outside the view's directory tree, back up the entire view storage directory tree. Use the local address or the networkwide address listed by lsview in Step #1.

If you are backing up a snapshot view and its view storage directory is outside the view's directory tree, be sure to back up both the view directory tree and the view storage directory.

NOTE: When you back up and later restore a snapshot view, it is important that the utility you use for the backup maintains the original modification times and ownership of all files and directories in the view. If it does not, loaded files become hijacked.

If the view's private storage area is remote, you need to perform a second backup (typically, using a different backup tape):

6. If you made the view read-only in Step #2, make it writable.

cleartool chview -readwrite akp_vu
Properties: readwrite

7. If you renamed the view storage directory in Step #2, rename it back to its registered location.