Hitachi MK-97DF8018-00 User Manual
Page 82
Glossary–10
Hitachi Simple Modular Storage Copy-on-Write SnapShot User’s Guide
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paired volume
Two volumes that are paired in a disk array.
parity
The technique of checking whether data has been lost or corrupted
when it's transferred from one place to another, such as between
storage units or between computers. It is an error detection scheme
that uses an extra checking bit, called the parity bit, to allow the
receiver to verify that the data is error free. Parity data in a RAID array
is data stored on member disks that can be used for regenerating any
user data that becomes inaccessible.
parity groups
RAID groups can contain single or multiple parity groups where the
parity group acts as a partition of that container.
peer-to-peer remote copy (PPRC)
A hardware-based solution for mirroring logical volumes from a primary
site (the application site) onto the volumes of a secondary site (the
recovery site).
point-in-time logical copy
A logical copy or snapshot of a volume at a point in time. This enables a
backup or mirroring application to run concurrently with the system.
pool volume
Used to store backup versions of files, archive copies of files, and files
migrated from other storage.
primary or local site
The host computer where the primary volume of a remote copy pair
(primary and secondary volume) resides. The term "primary site" is
also used for host failover operations. In that case, the primary site is
the host computer where the production applications are running, and
the secondary site is where the backup applications run when the
applications on the primary site fail, or where the primary site itself
fails.
primary volume (P-VOL)
The storage volume in a volume pair. It is used as the source of a copy
operation. In copy operations a copy source volume is called the P-VOL
while the copy destination volume is called "S-VOL" (secondary
volume).
P-VOL
See primary volume.