Hitachi Virtual Storage Platform G400, Reference Manual

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on both sides. If either one of MCU or RCU is USP V/VM, the
function cannot be applied.
(5) For a TC Sync or GAD pair with the mode effective (RI/O
MIH time is 5 seconds), the setting of RI/O MIH time made
at RCU registration (default is 15 seconds, which can be
changed within range from 10 to 100 seconds) is invalid.
However, RI/O MIH time displayed on 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 DKCs,
Open server time-out may occur.
(7) If an MP to which the path between DKCs belongs is
overloaded, switching to an alternate path delays and 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, time-out may occur due to response time
accumulation for each RI/O retried within 5 seconds.
(9) Even though the mode is set to ON, if Open host time-
out time is set to 10 seconds or less, time-out may occur
due to a path failure between DKCs.
(10) Operation commands are not available for promptly
switching to an alternate path.
(11) The mode 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 Sync pairs are
suspended or deleted.
(13) See System Option Mode 784 sheet for operational
specifications in each combination of MCU and RCU of TC.
(14) For GAD pairs, the mode is effective if the microcode is
in a version that supports GAD.
(15) The mode does not support paths between DKCs using
iSCSI in VSP Gx00/Fx00. (Configuration where DKC paths of
Fibre and iSCSI coexist is not supported.)
803
While a DP pool VOL is blocked, if a read or write I/O is
issued to the blocked pool VOL, this mode 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:
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.
OFF
68 System option modes
Hitachi Virtual Storage Platform G400, G600 Hardware Reference Guide