Hitachi AMS2100 User Manual page 43

Paired
(Includ-
Paired
SnapShot P_VOL
Inter-
chroniz-
Paired
R/W
x
Reverse Synchro-
nizing
Split
R/W
R/W
Failure
x
Failure (Restore)
Hitachi AMS 2000 Family Copy-on-Write SnapShot User Guide
Table 1-7: A Read/Write Instruction to a P-VOL of
Reve
ing
rse
Synchro- Syn-
nizing chro-
naly
nizin
Syn-
ing)
x
R/W
x x
R/W R/W
R/W R/W
x x
indicates a possible case, x indicates an impossible case
∆
indicates a case where a pair operation causes an error (a case that
can occur as a result of a change of the pair status to Failure)
R/W: Read/Write by a host is possible.
R: Read by a host is possible but write is impossible.
W: Write by a host is possible but read is impossible.
R/W: Read/Write by a host is impossible.
SnapShot overview
ShadowImage
ShadowImage P_VOL
Split
Split Pend-
ing
g
R/W R/W
x
R/W
R/W R/W
R/W R/W
∆
x
R/W
Failure Failure
Failure (Restor (S_VOL
e) Switch)
x x
R/W
x x
R/W
∆
x
?
R/W R/W
∆
R/W R/W R/W
∆
x x
R/W
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