Managing file migration

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How to manage file migration with the IBM Storage Archive Enterprise Edition.

IBM Storage Scale policies are used to specify files in the GPFS namespace to migrate to the IBM Storage Archive tape tier. For each specified GPFS file, the following information is stored in IBM Storage Archive EE so that it can be re-created when the files are imported back to GPFS:
  • The file content
  • The GPFS path
  • The GPFS metadata for the file (but no file permissions)
  • The user-defined extended attributes

Access control lists (ACLs), and permissions, are not stored on tape.

Although empty GPFS directories, empty regular files, and symbolic links are not migrated, they can be saved. For more information, see Managing file save.

Additional information about, and examples of, IBM Storage Scale policies that are used with IBM Storage Archive EE can be found in the white paper IBM Storage Scale Information Lifecycle Management Policies - Practical guide, https://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/WP102642.

In addition, it is possible to migrate files directly to target storage pools by using the eeadm migrate command. Select the files to migrate by specifying an input file list and a target tape storage pool, or pools. The file list must be in the record format of the mmapplypolicy.

Notes:
  • A file must be older than 2 minutes before it can be migrated. If you try to migrate the file sooner, the migration fails. You can retry the migration operation later.
  • Small files that fit into an inode can be migrated by IBM Storage Archive EE. The files are no longer stored in the inode after they are migrated.
  • The space management dsmmigrate command is not supported.

Configuring and activating migration

To migrate files, the following configuration and activation prerequisites must be met:
  • Ensure that the multi-tape management module (MMM) service is running on a IBM Storage Archive EE node. For more information, see Getting the system health status.
  • Ensure that tape storage pools are created and defined. For more information, see Managing tape storage pools.
  • Ensure that space management is turned on. For more information, see Retrieving status information for HSM daemons.
  • Activate one of the following mechanisms to trigger migration:
    • Automated GPFS policy-driven migration
    • Manual policy-based migration
    • Manual migration by using a prepared list of files and tape storage pools