User's Manual

hp StorageWorks File System Extender User Guide 13
FSE operations
FSE main operations are migration, release, recall, and deletion. They are configured with user-defined
policies. For more information on configuring policies, see ”Migration, release, recall, and deletion” on
page 109. After they are configured, the policies enable automatic, unattended execution of the
corresponding operations. However, these operations can also be triggered manually using the fsefile
command. For details on manual triggering, see the FSE Command-Line Reference.
Regardless of how they are invoked, the migration, recall, and deletion operations are represented and
controlled in the FSE implementation by so-called FSE jobs. Using the fsejob command, an FSE
administrator can display information about existing jobs or manipulate them. Example situations when
such manipulation is needed are the following:
• the priority of a particular recall job has to be increased, because urgently needed documents have to
be recalled from FSE media, and there are currently other jobs with higher priorities running in the FSE
implementation.
• a library in the FSE implementation has run out of FSE media and therefore additional media need to
be added to it and initialized, in order to get the media available and migration jobs running again.
For details on monitoring FSE jobs, see ”Monitoring FSE jobs” on page 139. For more information about
the fsejob command, see the FSE Command-Line Reference.
Migration
Migration is a process of copying files from the HSM file system to FSE media. If a file is not modified for a
configured period of time, it passes the so-called file age check and becomes a candidate for migration
(migration candidate).
Migration is done in two steps:
1. Files from the migration candidate list are copied from the HSM file system to a temporary location on
the FSE server, called a disk buffer. The disk buffer location is platform-dependent.
Linux specific
The disk buffer is located in the /var/opt/fse/diskbuf directory.
Windows specific
The disk buffer is located in the %InstallPath%\var\diskbuf directory.
The value of %InstallPath% depends on the path selection during FSE installation. It defaults to
C:\Program Files\Hewlett-Packard\FSE.
2. Data from this temporary location is copied to FSE media. To have redundant copies of the file data
made during the migration job, the respective FSE partition must have multiple media pools assigned to
it. For more information, see ”Multiple copying” on page 131.
Once the migration job is completed, the temporary location is cleared. The file entry in the Hierarchical
Storage Manager (HSM) is moved from the migration candidate list to the release candidate list.
For further information on migration process and its configuration, see chapter ”Migration, release, recall,
and deletion” on page 109.
Release
Release is a process following migration or recall, during which a file data is removed from the HSM file
system, leaving only the file header. FSE starts a release according to watermark parameters. For more
information, see ”Watermarks” on page 114.
Once the file is copied to FSE media, it becomes a release candidate. FSE checks the release candidates
for changes. If a file on the release candidate list was not modified, and a high watermark is reached on
the HSM file system, the content (file data) of the file is removed from the HSM file system to free disk
space. The same thing happens if a critical watermark is reached, but in this case all migrated files are
released, regardless of how much time has passed since their last migration.
Once the release operation is completed, the file is offline and its file entry is removed from the release
candidate list.