Hitachi VSP G200 System Administration Manual page 368

Mode Category
803 Dynamic
Provisioning
Data Retention
Utility
368
System Administrator Guide for VSP Gx00 models and VSP Fx00 models
Manager - Storage Navigator and CCI is not "5 seconds"
but is what set at RI/O registration.
6. If a failure occurs on the switched path between storage
systems, Mainframe host MIH or Open server time-out
may occur.
7. If an MP to which the path between storage systems
belongs is overloaded, switching to an alternate path
delays and host MIH or time-out may occur.
8. If an RI/O retry occurs due to other factors than RI/O
MIH (5 sec), such as a check condition report issued
from RCU to MCU, the RI/O retry is performed on the
same path instead of an alternate path. If a response
delay to the RI/O occurs constantly on this path due to
path failure or link delay, host MIH or time-out may
occur due to response time accumulation for each RI/O
retried within 5 seconds.
9. Even though this SOM is set to ON, if Mainframe host
MIH time or Open host time-out time is set to 10
seconds or less, host MIH or time-out may occur due to
a path failure between storage systems.
10. Operation commands are not available for promptly
switching to an alternate path.
11. This SOM works for the pair for which initial pair
creation or Resync operation is executed.
12. Micro-program downgrade to an unsupported version
cannot be executed unless all the TC and GAD pairs are
suspended or deleted.
13. For operational specifications in each combination of
MCU and RCU of TC, contact customer support (see
SOM784 sheet).
14. For GAD pairs, this SOM is effective if the microcode
version supports GAD.
15. This SOM does not support iSCSI paths between
storage systems. When iSCSI is used for paths between
storage systems, the time to switch to an alternate path
cannot be reduced. For this, if a failure occurs on a path
between storage systems in an environment where host
time-out time is short, a time-out may occur on the
host side. A time-out may also occur on the host side
when a failure occurs on an iSCSI path between storage
systems if storage system paths of Fibre and iSCSI
coexist in an environment where host time-out time is
short so that the configuration where storage system
paths of Fibre and iSCSI coexist is not supported too.
While a DP pool VOL is blocked, if a read or write I/O is
issued to the blocked pool VOL, this SOM can enable the
Protect attribute of DRU for the target DP-VOL.
Mode 803 = ON: While a DP pool VOL is blocked, if a read
or write I/O is issued to the blocked pool VOL, the DRU
attribute is set to Protect.
Mode 803 = OFF (default): While a DP pool VOL is
blocked, if a read or write I/O is issued to the blocked pool
VOL, the DRU attribute is not set to Protect.
System option modes
Description Default MCU/RCU
OFF -