Using HSM with Network Filesystem (NFS) Clients

When Backup migrates a file, it leaves a stub file on the original client filesystem. The stub file is a UNIX symbolic link that points to the new location of the migrated file. Because the stub files that Backup creates are symbolic links, NFS (network filesystem) clients cannot premigrate or migrate files on an NFS-mounted directory.

An NFS client, however, might need to recall previously migrated files from an NFS-mounted directory. Backup allows this operation under the following configuration:

• The NFS server must be a Solaris computer running the Backup client software and have a Migration Setup configured for it.

• The NFS client must be a Solaris computer running the Backup client software and have a Migration Setup configured for it.

• Both the NFS server and the NFS client must be configured as clients to the same Backup server.

• The NFS client must have the correct user/group available and have write privileges on the NFS-mounted directory.

• The NFS server must list the NFS client as a Remote Access User in its Backup client resource.

Figure 8-1 illustrates this configuration scenario.

Figure 8-1 Configuration Scenario For NFS and Migration Clients

In this scenario, the host Oak is a Backup server with the HSM module enabled and Elm and Pine on its list of clients. The host Elm is an NFS server that has the Backup client software running on it and Migration Setup configured for it, which makes it a Backup migration client. Pine is an NFS client that receives NFS services from Elm. Pine also has the Backup client software running on it and a Migration Setup configured for it, which makes it a Backup migration client.

For Pine to recall a file that has been migrated from Elm, Pine must be listed in the Remote Access attribute in Elm's Backup client resource. The recall operation recalls the migrated file from the migration store to the location of the stub file on Elm. This operation is transparent to the user.

If an NFS client does not meet these configuration criteria, you can use the rlogin command to log on to the NFS server and recall the file by performing any read or write operation on it. The migrated file is automatically recalled to its original location.