Apple Xsan 1.0 - Manual (Page 107)

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Glossar
y Glossary
ACFS Apple Cluster File System. The underlying Xsan file system. ACFS is a shared SAN
file system that uses a controller to manage file system metadata. Derived from ADIC’s
StorNext File System.
affinity An association between a folder on an Xsan volume and one of the storage
pools that make up the volume. The affinity guarantees that files placed in the folder
are stored only on that storage pool.
allocation strategy In Xsan, the order in which data is written to the storage pools that
make up a volume. Can be fill, round robin, or balance.
Apple Cluster File System See ACFS.
balance An Xsan storage pool allocation strategy. Before allocating space on a volume
consisting of more than one storage pool, Xsan analyzes available storage on all pools
and uses the one with the most available space.
block allocation size An Xsan volume property. The smallest number of bytes that can
be reserved on, written to, or read from an Xsan volume.
client A computer that accesses data on an Xsan volume. A SAN administrator must
add the client to the SAN and mount a volume on the client before the client can
access SAN data.
controller In Xsan, short for “metadata controller.” See “metadata controller.”
failover In Xsan, the automatic process by which a standby Xsan controller becomes
the active metadata controller for a volume if the volume’s primary controller fails.
failover priority An Xsan controller property. In a SAN with more than one controller,
specifies which standby controller to try first during failover.
file system A scheme for storing data on storage devices that allows applications to
read and write files without having to deal with lower-level details. This is the term the
StorNext File System uses for an Xsan volume.
file system server See FSS.
LL0192.book Page 107 Thursday, July 29, 2004 5:20 PM