HP D5970A - NetServer - LCII Installation And User Manual page 156

Appendix B
assignments are per host port and are independent of the assignments on other
host ports. Logical drives may be assigned only one LUN per host port.
By not assigning a LUN to a logical drive on a particular host port, that logical
drive is made inaccessible to that host port.
Logical Drive States
The state of a logical (system) drive can be either ONLINE, CRITICAL, or
OFFLINE. Notice that the same term "online" is used for both physical and
logical drives.
Online: A Logical Drive is in an "online" state if...
All of its member drives are "online."
Critical: A Logical Drive is in a "critical" state if...
It has been configured at RAID level 1, 3, 5, or 0+1; and One (and only
one) of its member drives is not "online."
A logical drive is considered "critical" because any failure of another of its
member drives may result in a loss of data.
I/O operation can only be performed with logical drives that are online or
critical.
Offline: A Logical Drive is in an "offline" state if...
No data can be read from it or written to it.
System commands issued to offline logical drives are returned with an
error status: no operations can be performed on offline logical drives. A
logical drive can be "offline" under one of two situations described below:
It is configured with a redundant RAID level (1, 3, 5, or 0+1) and two
or more of its member drives are not "online"; or
It is configured at RAID level 0 or JBOD, and one or more of its
member drives are not "online."
Logical Drives
A logical drive is equivalent to a "system" drive. Logical drives are presented to
the operating system as available disk drives, each with a capacity specified by the
disk array controller.
Logical Unit Number (LUN)
A SCSI representation of a system drive (logical drive) on a given channel and
target ID.
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Glossary