Installation guide

Glossary
Manual No. 771961 G-3
error. If the write fails (media error on write), the controller issues a
“reassign” command to the disk, and then writes the data to a new location.
Since the problem has been resolved, no error is reported to the system.
When a disk reports a media error during a write, the controller issues a
“reassign” command to the disk, and writes the data out to a new location on
the disk.
Drive Groups (or Drive Packs)
A drive group is a group of individual disk drives (preferably identical) that
are logically tied to each other and are addressed as a single unit. In some
cases this may be called a drive “pack” when referring to just the physical
devices.
All the physical devices in a drive group should have the same size,
otherwise each of the disks in the group will effectively have the capacity of
the smallest member. The total size of the drive group will be the size of the
smallest disk in the group multiplied by the number of disks in the group.
For example, if you have 4 disks of 400MB each, and 1 disk of 200MB in a
pack, the effective capacity available for use is only 1000MB (4*200), not
1800MB
Dual-Active (Duplex) Mode
A method of interconnecting multiple RAID controllers that share a
common set of drives. In addition to increasing overall performance, this
method allows a surviving controller to take over resources of a failed
controller. This “failover” process is transparent to the host.
Duplex Mode
See “Dual-Active (Duplex) Mode” .
Error Table
See “Bad Block Table (or Bad Data Table)”.