NEC IS015-9E Computer Accessories User Manual


 
Chapter 2 Data Replication
8
Chapter 2 Data Replication
This chapter describes the types and state transitions of volumes that are necessary to perform operation using the
Data Replication function.
2
2
2
.
.
.
1
1
1
V
V
V
o
o
o
l
l
l
u
u
u
m
m
m
e
e
e
C
C
C
l
l
l
a
a
a
s
s
s
s
s
s
i
i
i
f
f
f
i
i
i
c
c
c
a
a
a
t
t
t
i
i
i
o
o
o
n
n
n
To create replication volumes using the Data Replication function, you must set the relation between
the original volume and the target volume (replication volume) first. In replication control, the
original volume is called MV (Master Volume), and replication volume is called RV (Replication
Volume). Furthermore, MV and RV are set as a pair.
In a disk array to which the Data Replication function is installed, the volume classification in the disk
array is categorized into the following three types. Figure 2-1 describes sample volume classification.
Isolated Volume (IV)
Volume with no pair setting.
By specifying the pair setting to IV, you can set it to MV or RV.
Master Volume (MV)
Volume with the pair setting. The original volume in the pair. Normally, volumes used in
operation are set as MVs.
To distinguish the uppermost MV from other MVs when multiple pairs are set in series hierarchically,
it is called the Primary Volume (PV).
Replication Volume (RV)
Volume with the pair setting. The target volume in the pair. Normally, volumes used as backup or
in test operation are set as RVs.
The pair setting can be between the volumes within the same disk array, or between the volumes in
different disk arrays. To distinguish them, the former is called a Dynamic Replication Volume
(dRV) and the latter is called a Remote Replication Volume (rRV).