HP StorageWorks File Migration Agent V2.1 administrator guide (T4274-96105, October 2006)

22 Product information
Migration
Files are migrated to one or more archives by FMA based on policies set by the administrator. Any number
of policies can be set on each volume managed by FMA. The policies are based on file name (wildcards
are usable, for example, *.exe or a*.txt), file age in relation to creation, modification or last access time,
or a minimum file size. Files may be excluded from migration by file name or file attributes (for example,
hidden files).
Each migration policy is valid for a directory of the managed volume and all its subdirectories. A policy
attached to the root directory will therefore apply to the entire volume.
Migration policies are applied by FMA through its policy process. The policy process can be freely
scheduled by the administrator to run at regular intervals. The intervals can range from multiple times a
day to once a year. The policy process can also be started manually.
Files may also be migrated explicitly via the FMA command line interface, or by using the Windows File
Explorer plug-in.
During the archiving process files are opened exclusively to ensure that the data is consistent. Archiving
does not lock files exclusively. After the file is archived, the file size and the time stamps are checked to
validate the archive copy.
Release
FMA monitors the space available on managed volumes. The administrator must set three watermark levels
(in %) for each volume: low, high, and critical. When the high watermark level is reached, FMA will
release files until the low Watermark level is reached. The decision which files to release is based on the
defined volume retention policies. The administrator may specify these retention policies per volume.
Retention policies are related to elapsed time since last access or modification to a file.
If the critical watermark is reached, files are released independently of the retention policies.
FMA monitors the space on a volume at administrator-defined intervals.
Files may also be released explicitly via the FMA command line interface, or by using the Windows File
Explorer plug-in.
Only files that have at least one valid archive copy can be released. Releasing locks files exclusively. Files
that cannot be opened exclusively cannot be released and will remain online.
Files with a size of below 1024 Byte will never be released.
Recall
Whenever a user or application accesses an offline file to read its data, FMA will intercept the read
request and will first retrieve the file’s data from the archive. If an archive is not available FMA will try data
copies in other archives if there are any.
Such copies can either be created by FMA via migration to more than one archive or by the archive itself
via replication. For the latter case, FMA lets the administrator define an alternate (that is, replicated)
archive from which to retrieve data.
If a file cannot be recalled from any of the archives, an FMA error code (see ”FMA error handling” on
page 146) will be returned.
Files may also be recalled explicitly via the FMA command line interface, or by using the Windows File
Explorer plug-in.