HP XP Continuous Access Software - Manual (Page 21)

Description 21
SnapShot employs two techniques:
• creating or mapping a virtual volume (V-VOL)
• copy on write to a SnapShot pool volume (pool-VOL) identified by a
pool ID.
SnapShot does not require any new RM commands, it uses current BC
commands with new arguments.
Note: SnapShot is used in Unix and Windows environments only. SnapShot does
not work in MPE/iX and OpenVMS environments.
The following figure illustrates the basic concept.
Pairs and pair management
Both BC (non-SnapShot) and CA continuously copy data from a primary
source volume known as a P-VOL to a secondary volume known as an
S-VOL.