User's Manual

HP StorageWorks File System Extender Software user guide 113
In the example, the first medium volume on the FSE medium with barcode 052002 was recycled during the
reorganization job and can be reused.
Before recycled medium volumes can be reused, they must be reinitialized. The reinitialization is performed
automatically at the end of the FSE reorganization job. All recycled medium volumes are reinitialized in
sequence. If the reorganization job has been terminated for some reason before medium volume
reinitialization, you have to reinitialize the recycled volumes manually. For more information on initializing
FSE medium volumes, see section ”Initializing media” on page 103 and the FSE CLI reference.
Recreating redundant copies of migrated data
FSE enables you to assign several FSE media pools to the same FSE partition, in order to store multiple
copies of the migrated data on FSE media (via the Pools variable in the FSE partition configuration file).
In such a configuration, each media pool contains one copy of the migrated data from the HSM file
system.
Having multiple copies of the migrated data is useful for various reasons, including the possibility of storing
a particular copy in a vault and increasing the overall safety of the migrated data. For information on
configuring multiple copies, see ”Multiple copying” on page 147.
Since tape media wear out over time, some can eventually become unusable. Migrated file generations on
such media can no longer be recalled. In effect, this means that one copy of the migrated data is lost. FSE
enables you to recover the damaged copy, provided that such data was migrated from an FSE partition for
which multiple copying was configured. This process is called recreating a redundant copy and is
available for FSE tape media and FSE disk media.
By recreating the redundant copy of the damaged migrated data, you can restore the availability and
safety of the migrated data.
The redundant copy recreation process
Redundant copy recreation is started by the fsemedium command and performed by the FSE
maintenance job. The process first scans the File System Catalog (FSC) to find the file generations that were
migrated to the specified medium, searches for alternative redundant copies in the same or other FSE
media pools, and then remigrates data to the FSE media pool of the unreadable medium. Note that the
052002 2 data 5949 5949 60 open, scanned
052002 3 data 5949 5949 0 empty
052002 4 data 5949 5949 0 empty
052002 5 system 1019 1019 0 open