Tivoli Storage Manager for Space Management client overview

The IBM® Tivoli® Storage Manager for Space Management client migrates files from your local file system to Tivoli Storage Manager server storage and can then recall the files either automatically or selectively. Migrating files to storage frees space for new data on your local file system and takes advantage of lower-cost storage resources that are available in your network environment.

The figure shows an overview of hierarchical storage management.

Figure 1. Overview of hierarchical storage management

When a file is migrated from your local system to Tivoli Storage Manager server storage, a placeholder, or stub file, is created in place of the original file. Stub files contain the necessary information to recall your migrated files and remain on your local file system. The migrated files appear to be on your local file system. This process contrasts with archiving, where you usually delete files from your local file system after you archive them.

The Tivoli Storage Manager for Space Management client provides space management services for locally mounted file systems, and it migrates regular files only. It does not migrate character special files, block special files, named pipe files, or directories.

File migration, unlike file backup, does not protect against accidental file deletion, file corruption, or disk failure. Continue to back up your files regardless of whether they are on your local file system or are migrated to Tivoli Storage Manager server storage. The IBM Tivoli Storage Manager backup-archive client backs up and restores resident and migrated files. If you accidentally delete stub files from your local file system, or if you lose your local file system, you can restore the stub files or the complete files.

For planned processes, such as storing a large group of files in storage and returning them to your local file system for processing, use the archive and retrieve processes. The backup-archive client is used to archive and retrieve copies of migrated files.

The Tivoli Storage Manager for Space Management client functions for threshold migration, demand migration, selective migration, selective and transparent recall includes processing GPFS™ file systems that contain multiple space-managed storage pools.

The Tivoli Storage Manager for Space Management client has commands that you can run from a shell. You can also use the commands in scripts and cron jobs.

For example, the following commands migrate all files that are owned by user ibm:

  find /hsmmanagedfilesystem -user ibm -print > /tmp/filelist
  dsmmigrate -filelist=/tmp/filelist

Your Tivoli Storage Manager server administrator associates management classes with your files. You, as a root user, can do the following tasks:

• Select space management options and settings.
• Assign management classes to your files.
• Exclude files from space management.
• Schedule space management services.