HP File System Extender (FSE) manual See LTO Ultrium, Unusable medium, Worm file system

tool	A command that communicates directly with FSE daemons (services) and agents besides
(FSE tool)	Management Interface, designed for low-level modifications and more extensive monitoring
	and troubleshooting tasks. FSE tools are only intended for use by experienced FSE users
	(typically on request of technical support personnel of FSE). Note that incorrect use of FSE tools
	can cause data corruption. FSE tools are located in the directory /opt/fse/sbin/tools (on
	Linux platform) or in the directory %InstallPath%\bin (on Windows platform).
Ultrium	See ”LTO Ultrium”.
unreliable medium	An FSE medium to which further writing is disabled, but from which FSE is still able to read
	data. As soon as the first write error is detected while the Back End Agent is writing data to the
	medium, the medium is automatically marked as unreliable in the Resource Management
	Database. Such errors usually occur because of an excessive use of the medium.
unusable medium	An FSE medium which has been disabled for both writing to and reading from. As soon as the
	first read error is detected while the Back End Agent is reading data from the medium, the
	medium is automatically marked as unusable in the Resource Management Database. Such
	errors usually occur because of an extremely excessive use of the medium.
user	A computer system user who uses one or more HSM file systems for managing data.
(FSE user)
utility	An add-on FSE component that provides additional functionality and complements basic FSE
(FSE utility)	components. In current FSE release, two FSE utilities are part of the FSE software: HSM Health
	Monitor and Log Analyzer. See also ”HSM Health Monitor (HHM)”, ”Log Analyzer (LA)”.
verified drive	An FSE drive that is put back in operation after its problems have been resolved. This is done
	by changing its status in the Resource Management Database to online. The online status
	is set by enabling the drive with the fsedrive command.
WORM file system	A file system on which a file can be written only once, but can be read many times. A WORM
	(Write Once Read Many) file system prevents both files and their metadata from being
	modified, regardless of their access permissions. Consequently, it is not possible to remove files
	from directories or rename them; it is only possible to add new files (as on a regular file
	system). Files and directory operations are restricted to read-only after a period of time. A
	WORM partition must be related to WORM media pools containing WORM media only.
WORM medium	On a WORM (Write Once Read Many) medium, data can be recorded only once. Once
	recorded, the WORM medium cannot be overwritten, reformatted, or reinitialized, but new
	data can be appended to the existing contents. A WORM medium can only be initialized in a
	WORM media pool.

HP StorageWorks File System Extender Software user guide 319