Tivoli Header

Tivoli Space Manager for UNIX Using the Hierarchical Storage Management Clients


Migrating Files from Your Local File System

Once file migration begins, the HSM client sends a copy of your file to a server and replaces the original file with a stub file on your local file system. The file appears as though it resides on your local file system. A stub file is a small file that contains required information to locate and recall a migrated file, and to respond to specific UNIX commands without recalling the file. The server places your migrated files in storage volumes on disk devices, or devices that support removable media, such as tape. Your TSM administrator defines and groups the storage volumes into storage pools.

The HSM client provides both automatic and selective migration. Automatic migration monitors space usage and automatically migrates eligible files according to the options and settings that you select. The HSM client provides two types of automatic migration: threshold migration and demand migration.

Threshold migration maintains a specific level of free space on your local file system. When space usage reaches the high threshold that you set for your file system, eligible files begin migrating to storage automatically. When space usage drops to the low threshold that you set for your file system, files stop migrating.

Demand migration responds to an out-of-space condition on your local file system. Threshold migration starts automatically if your file system runs out of space. As files migrate, space becomes available on your file system and the process that caused the out-of-space condition continues.

Selective migration moves specific files from your local file system to storage. For example, if you know that you will not be using a particular group of files for an extended time, you can migrate them to storage to free additional space on your local file system.


[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]