Hitachi Universal Storage Platform VM - Manual (Page 59)

Functional and Operational Characteristics 3-15
Hitachi Universal Storage Platform V/VM User and Reference Guide
Mode Category Function Default MCU/RCU
460 TrueCopy,
TrueCopy for z/OS
ShadowImage,
ShadowImage for
z/OS
Universal
Replicator,
Universal
Replicator for z/OS
Volume Migration
FlashCopy v1, v2
COW Snapshot
Dynamic
Provisioning When turning off PS, the control information of the following
PPs stored in shared memory will be backed up in SVP. After
that, when performing volatile PS ON, the control information
will be restored into shared memory from SVP.
TrueCopy, TrueCopy for z/OS, ShadowImage, ShadowImage
for z/OS, Volume Migration, FlashCopy v1, FlashCopy v2,
Universal Replicator, Universal Replicator for z/OS, COW
Snapshot, Dynamic Provisioning.
Setting Mode 460 to ON is required to enable the function.
Note:
1. Set mode 460 to ON when using any of the PPs listed
above.
2. In case of mode 460 ON, the completion time of PS-OFF for
SM backup or the completion time of volatile PS-ON after
SM recovery takes up to 30 minutes.
3. When using power monitoring devices (PCI, etc.), the
monitoring time for PS-OFF/ON must be set to the
maximum of 30 minutes.
4. When the storage system is powered off automatically at
power outage while destage mode is ON, SM is not backed
up to the SVP even though mode 460 is set to ON.
5. In the case of using Dynamic Provisioning: With DKCMAIN
version 60-02-04-00/00 and higher, the DP management
information is stored in a dedicated area in the pool in case
data are lost from the SM. However, restoring the data
from the dedicated area in the pool may take more time
than restoring the data from the SVP. Therefore, setting
mode 460 to ON is recommended to enable the data
backup and recovery function from the SVP.
OFF MCU/RCU
464 TrueCopy for z/OS SIM Report without Inflow Limit
For TrueCopy for z/OS, the SIM report for the volume without
inflow limit is available when mode 464 is set to ON.
SIM: RC=490x-yy (x=CU#, yy=LDEV#) OFF MCU
466 Universal
Replicator,
Universal
Replicator for z/OS For UR/URz operations it is strongly recommended that the
path between main and remote storage systems have a
minimum data transfer speed of 100 Mbps. If the data
transfer speed falls to 10 Mbps or lower, UR operations cannot
be properly processed. As a result, many retries occur and UR
pairs may be suspended. Mode 466 is provided to ensure
proper system operation for data transfer speeds of at least
10 Mbps.
Mode 466 = ON: Data transfer speeds of 10 Mbps and higher
are supported. The JNL read is performed with 4-multiplexed
read size of 256 KB.
Mode 466 = OFF: For conventional operations. Data transfer
speeds of 100 Mbps and higher are supported. The JNL read is
performed with 32-multiplexed read size of 1 MB by default.
Note: The data transfer speed can be changed using the
Change JNL Group options. OFF –