2.3 ClearCase Data and Non-ClearCase Hosts

A host on which ClearCase has not been installed can still access VOB data. There are several ways to provide this access, some more restrictive than others:

• Use a snapshot view on a ClearCase host. You can use this method when the non-ClearCase host can use a remote file access facility, such as NFS or Microsoft Windows networking, to access files in the snapshot view directory.

This method offers good performance because it uses native software for remote file access. However, you are restricted to those element versions that the snapshot view selects, you cannot use version-extended or view-extended pathnames, and you cannot run ClearCase tools such as clearmake on the non-ClearCase host.

To use this method:

1. On a ClearCase host, create a snapshot view and load into it the files you want to access from a non-ClearCase host.

2. On this host, make the files accessible to other hosts on your network. For a UNIX host, export the file system on which the snapshot view directory resides. For a Windows host, share the drive or directory on which the snapshot view directory resides.

3. On a non-ClearCase host, use remote file access to read and write files in the snapshot view directory.

4. To modify VOB data, check out and check in versions in the snapshot view on the ClearCase host.

• Use the ClearCase Web interface. You can use this method when the non-ClearCase host has a browser that the ClearCase Web interface supports and when a ClearCase host is configured as a Web server for the ClearCase interface. You can use the Web interface to modify VOB data without running ClearCase tools on the non-ClearCase host. For information about setting up the Web interface, see Chapter 29, Configuring a Web Server for the ClearCase Web Interface.

• Use non-ClearCase access (UNIX only). On UNIX hosts, you can use this method when the non-ClearCase host implements the NFS client protocol. Performance is slower than accessing a snapshot view through NFS because the MVFS, a view server, and the disk-based file system take part in each file access. It also cannot faithfully implement some parts of the NFS protocol. Because of these limitations, snapshot views and the ClearCase Web interface, when available, are preferable methods for accessing VOB data. For information on non-ClearCase access, see Using Non-ClearCase Access on UNIX Hosts.