Lenovo ThinkServer RD240 Software User's Manual page 354

IO policy
learning cycle
load-balancing
media error
count
migration
mirroring
multipathing
name
non-redundant
configuration
B-6
A virtual drive property indicating whether Cached I/O or Direct I/O is
being used. In Cached I/O mode, all reads are buffered in cache
memory. In Direct I/O mode, reads are not buffered in cache memory.
Data is transferred to cache and the host concurrently. If the same data
block is read again, it comes from cache memory. (The IO Policy applies
to reads on a specific virtual drive. It does not affect the read ahead
cache.)
A battery calibration operation performed by a RAID controller
periodically to determine the condition of the battery.
A method of spreading work between two or more computers, network
links, CPUs, drives, or other resources. Load balancing is used to
maximize resource use, throughput, or response time.
A drive property indicating the number of errors that have been detected
on the drive media.
The process of moving virtual drives and hot spare drives from one
controller to another by disconnecting the drives from one controller and
attaching them to another one. The firmware on the new controller will
detect and retain the virtual drive information on the drives.
The process of providing complete data redundancy with two drives by
maintaining an exact copy of one drive's data on the second drive. If one
drive fails, the contents of the other drive can be used to maintain the
integrity of the system and to rebuild the failed drive.
The firmware provides support for detecting and using multiple paths
from the RAID controllers to the SAS devices that are in enclosures.
Devices connected to enclosures have multiple paths to them. With
redundant paths to the same port of a device, if one path fails, another
path can be used to communicate between the controller and the device.
Using multiple paths with load balancing, instead of a single path, can
increase reliability through redundancy.
A virtual drive property indicating the user-assigned name of the virtual
drive.
A RAID 0 virtual drive with data striped across two or more drives but
without drive mirroring or parity. This provides for high data throughput
but offers no protection in case of a drive failure.
Glossary