HP StorageWorks Command Console V2.5 User Guide (AA-RV1UA-TE, March 2005)

Glossary
130 Command Console V2.5 User Guide
device group A logical, internal controller structure representing one or more
devices that are linked as a group. Some controllers require that
you must create device groups before you can create a virtual
disk from them. Device groups are also known as containers.
There are different types of device groups:
■ Single-device virtual disks (JBODs)
■ Striped virtual disks (RAID 0)
■ Mirrored virtual disks (RAID 1)
■ Striped mirrored virtual disks (RAID 0+1)
■ Striped parity virtual disks with parity across all drives
(RAID 3/5)
■ Striped parity virtual disks with floating parity disk (RAID
5)
disk A storage device that uses rotating magnetic media to store
data.
disk array A collection of disk devices that are physically connected in an
ordered structure.
dual-redundant
configuration
For HS-series controllers, a configuration consisting of a
primary and backup controller in one controller shelf. If the
primary controller fails, the backup controller assumes control
of the failing controller's devices.
Environmental
Monitoring Unit (EMU)
Some subsystem enclosures include an environmental
monitoring unit that provides increased protection against
catastrophic faults. The EMU works with the controller to warn
about impending subsystem failures. The EMU senses such
conditions as failed power supplies, failed blowers, elevated
temperatures, and external air sense faults.
failed A device state indicating that a device is inoperable and
unavailable for use in a virtual disk. In some controllers, you
can force a failed state, for instance to remove the device from
the storage enclosure. In others, a device is marked as failed if
you remove it as a member of a virtual disk.