Chapter 16. Adjusting the ClearCase Startup/Shutdown Script

This chapter describes changes you can make to the ClearCase startup/shutdown script on any host where ClearCase is installed.

Name of Startup/Shutdown Script

The name of the ClearCase startup/shutdown script is architecture-dependent:


SunOS-4, HPUX-9


SunOS-5, IRIX-5



Changing VOB Mounts to “Release 1 Style”

One of the principal jobs of the ClearCase startup script is to mount VOBs as multiversion file systems (file system type MVFS). The way in which this is accomplished changed between ClearCase Release 1 and Release 2:

  • In Release 1, VOBs to be mounted by the startup script were listed in a ClearCase-specific file system table, implemented as file /etc/fstab.mfs. (This file could, in turn, incorporate the contents of an NIS map.)

  • In Release 2, all information necessary for mounting a VOB is stored in the network-wide storage registry. The fstab.mfs file is no longer required.

For compatibility, the Release 1 mechanism for mounting VOBs is still supported in Release 2 (though the file system type has been changed from “mfs” to “mvfs”). If a host was upgraded from Release 1 to Release 2, and you wish to have it continue to mount VOBs using the old mechanism, follow these steps:

  1. Edit the ClearCase startup script—This script's location and contents varies from architecture to architecture .

    # Mount /view and all public VOBs in the registry.
        mount -t mvfs -o rw,viewroot $VIEWPATH $VIEWPATH
        ${ATRIA}/bin/cleartool mount -a

    The first command—the one you should not touch—mounts the viewroot directory, /view, directly. In ClearCase Release 1, a file system table entry specified the mounting of this directory.

  2. Verify that there is no viewroot mount entry—ClearCase installation should have commented out any /view entry in your host's standard file system table (for example, /etc/fstab or /etc/vfstab). Such entries reflect ClearCase Release 1.1.x functionality that is not supported by Release 2. If necessary, remove such an entry manually.

  3. Revise the ClearCase file system table—Edit file /etc/fstab.mfs as follows:

    • Make sure it does not include any Release-1-style entries for mounting the viewroot directory.

    • Change all occurrences of the file system type mfs to mvfs.

Changing Dynamic Loading of the MVFS

Note: This section applies to SunOS 4 hosts only.

The ClearCase startup script has a “customer-editable section”, which is largely self-documenting. This section allows you to select among several invocations of the modload(8) utility, which dynamically loads the ClearCase MVFS code into the UNIX kernel.

The default modload invocation causes the MVFS to take the “TFS” slot in the virtual file system table (if no empty slot is available), and to use standard cache sizes. You can select either of these alternative invocations:

  • Use the “RFS” slot instead of the “TFS” slot—For an additional discussion, see the CASEVision/ClearCase Release Notes.

  • Configure larger MVFS caches—This is a performance-tuning measure. For an additional discussion, see “Improving Client Host Performance”.

The sections cited above also discuss other techniques for manipulating the virtual file system table, and for configuring MVFS caches.