Hitachi F1500, Руководство по оборудованию

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parity is computed by XOR'ing a bit from drive 1 with a bit from drive 2
and storing the result on drive 3. After a failed drive is replaced, the RAID
controller rebuilds the lost data from the other two drives. RAID systems
often have a "hot" spare drive ready and waiting to replace a drive that
fails.
parity group
See RAID group .
point-to-point
A topology where two points communicate.
port
An access point in a device where a link attaches.
primary site
The physical location of a storage system that contains original data to be
replicated and that is connected to one or more storage systems at a
remote or secondary site via remote copy connections. A primary site can
also be called a “main site” or “local site”.
The term "primary site" is also used for host failover operations. In that
case, the primary site is the location of the host on which the production
applications are running, and the secondary site is the location of the host
on which the backup applications that run when the applications at the
primary site have failed.
R
RAID
redundant array of independent disks
A collection of two or more disk drives that presents the image of a single
logical disk drive to the system. Part of the physical storage capacity is
used to store redundant information about user data stored on the
remainder of the storage capacity. In the event of a single device failure,
the data can be read or regenerated from the other disk drives.
RAID employs the technique of disk striping, which involves partitioning
each drive's storage space into units ranging from a sector (512 bytes) up
to several megabytes. The stripes of all the disks are interleaved and
addressed in order.
Glossary 201
Hitachi Virtual Storage Platform G1000, G1500, and Virtual Storage Platform F1500 Hardware Guide