Hitachi AMS2100 User Manual page 71

Table 2-3: Combination of a DP-VOL and a Normal LU
TrueCopy TrueCopy
P-VOL S-VOL
DP-VOL Normal LU
Normal LU DP-VOL
When creating the data pool using multiple DP-VOLs, the data pool
1
cannot be created by combining the DP-VOLs which have different
setting of Enabled/Disabled for Full Capacity Mode.
2
When both the P-VOL and the data pool use DP-VOLs, a pair cannot
be created by combining the DP-VOLs which have different setting of
Enabled/Disabled for Full Capacity Mode
• Assigning the controlled processor core of a P-VOL or a data pool
that uses the DP-VOL
When the controlled processor core of the DP-VOL used for a P-
VOL or used for a data pool of SnapShot differs as well as the
normal LU, switch the P-VOL controlled processor core
assignment to the data pool controlled processor core
automatically and create a pair. (In the case of AMS2500)
• DP pool designation of a P-VOL or a data pool that uses the DP-
VOL
When using the DP-VOL created by Dynamic Provisioning for a P-
VOL or a data pool of SnapShot, using the DP-VOL designated in
a separate DP pool of a P-VOL and a data pool is recommended.
• Setting the capacity when placing the DP-VOL in the data pool
When the pair status is Split, the old data is copied to the data
pool while writing to the P-VOL. When using the DP-VOL created
by Dynamic Provisioning as the data pool of SnapShot, the
consumed capacity of the DP-VOL in the data pool is increased by
storing the old data in the data pool. If the DP-VOL of more than
or equal to the DP pool capacity is created and used for the data
pool, this processing may deplete the DP pool capacity. When
using the DP-VOL for the data pool of SnapShot, it is
recommended to set the capacity making the over provisioning
ratio 100% or less so that the DP pool capacity does not deplete.
Furthermore, the threshold value of the data pool of SnapShot
and the threshold value of the DP pool differ. Even if the data pool
use rate of SnapShot shows 10% or less, the DP pool consumed
capacity may have exceeded Depletion Alert. Check whether the
actual use rate falls below the respective threshold values of the
data pool and DP pool of SnapShot.
• Pair status at the time of DP pool capacity depletion
Planning and design
Hitachi AMS 2000 Family Copy-on-Write SnapShot User Guide
1
Available. The P-VOL consumed capacity can be
reduced compared to the normal LU.
Available. When the pair status is Split, the data
pool consumed capacity can be reduced
compared to the normal LU.
Contents
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