Spectra Logic Spectra nTier300, Installation Manual

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Glossary of Terms – L
79
iSCSI Internet SCSI. iSCSI implements the SCSI command protocol over a
Ethernet interface (or any other IP-based network). iSCSI encapsulates
standard SCSI data blocks into the IP protocol, which allows block-
based SCSI data destined for disk- or tape-based storage to be
transmitted over a standard IP network.
L
LAN
Local Area Network. A communications network that serves a confined
geographical area. It attaches clients (users’ workstations) and servers
that hold programs and data shared by the clients.
LED
Light-Emitting Diode. It lights up when electricity passes through it.
logical drive
A section of disk storage that is seen by the host operating system as a
single physical drive. A logical drive might be located on one or more
physical drives.
LUN
Logical Unit Number. A unique identifier used by a SCSI device that
enables it to address up to eight separate devices (each of which is a
logical unit).
In the case of a RAID-protected disk array, a LUN represents the logical
disk created from the disk drives in a RAID set. A logical disk can be
created from either all of the space in the RAID set or just a slice of the
space (a disk partition).
M
Mb/sec
Megabits per second, a measure of data transfer speed.
MB/sec
Megabytes per second, a measure of data transfer speed.
mirroring
Mirroring is the process of creating and maintaining two or more
identical copies of data on separate media. For RAID-protected arrays,
mirroring refers to RAID 1.
N
N+1
A redundancy designation indicating that equipment is configured to
provide redundancy in the event a single component fails.