User's Manual

hp StorageWorks File System Extender User Guide 261
medium
(FSE medium)
A high-capacity magnetic tape, or a disk medium used by the FSE implementation. FSE medium
volumes are stored on tape partitions, in case of tape medium, or in file system subdirectories,
in case of disk medium. Tape medium is further divided into tape partitions and disk medium is
divided into subdirectories. Tape partitions store FSE medium volumes on a tape medium and
subdirectories store FSE medium volumes on a disk medium. FSE media represent the
secondary storage space in an FSE implementation. See also ”disk medium (FSE disk
medium)”.
medium volume
(FSE medium volume)
A physical partition on an FSE medium, with its own volume header. There are two types of
medium volumes: data volume and system volume. Data volumes store migrated file data, while
system volumes store redundant copies of Fast Recovery Information from all data volumes on
the medium. Each medium can have only one system volume and one or more data volumes.
migration candidate An online, dirty file that is scheduled for migration.
migration candidate
list
A list of files that were changed and have passed a certain period of time defined by the
migration policy, which are waiting for migration. The list is maintained by the Hierarchical
Storage Manager.
migration policy A set of rules by which the migration jobs for files on an HSM file system are initiated.
Configuration parameters for the respective policy are specified in the FSE partition
configuration file. Each FSE partition has its own migration policy.
migration retention
time
A period of time during which a migrated file is kept online before it is released. See also
”retention time”.
migration, migration
job
A process, executed by the Partition Manager, that copies the file contents from the HSM file
system to the FSE media. When the process is completed, the file entries of the migrated files
are moved from the migration candidate list to the release candidate list.
Name Space Catalog
(NSC)
A part of the File System Catalog. NSC includes metadata of files on an HSM file system, such
as directory structure, standard attributes, ownership (on Linux platform), and ACL (Access
Control List) and Alternate Data Streams (on Windows platform). This metadata enables
recovery of an HSM file system. See also ”File System Catalog (FSC)”.
Network File System
(NFS)
The file-sharing protocol used in UNIX networks. This is one of the protocols that can be used
for accessing files on an HSM file system from a remote machine, particularly a Linux client.
offline file A file whose contents were migrated to one or more FSE media (according to the number of
copies defined), and then removed from the HSM file system. The header and extended
attributes of an offline file are left intact and remain on the HSM file system. An offline file
becomes online at an FSE user's request, when its contents are recalled from the FSE media.
offline medium An FSE medium which is temporarily put out of operation and physically removed from the FSE
library.
online file A file on an HSM file system that is ready to be used by an application. A file is online
immediately after it is stored on the HSM file system, regardless of whether it was newly created
or recalled from FSE media. An online file becomes offline when it is released.
online medium An FSE medium that is put back in operation by being physically inserted into the FSE library
and having its status changed in the Resource Management Database to “online”. This online
status is set using the fsemedium command.
package
(FSE package)
A package with FSE software that will be installed to an FSE implementation.