User guide

B–10 System option modes
Hitachi Unified Storage VM Block Module Hardware User Guide
725 This option determines an action when Not Ready is
returned from the external volume.
Mode 725 = ON:
When Not Ready is returned, the external path is blocked
and the path status can be automatically recovered (Not
Ready blockade). Note that the two behaviors, automatic
recovery and blockade, may be repeated.
From version 60-05-06-00/00, the following is added.
For the device of Not Ready blockade, the Device Health
Check is executed after 30 seconds.
Mode 725 = OFF (default):
When Not Ready is returned 3 times in 3 minutes, the
path is blocked and the path status cannot be
automatically recovered (Response error blockade).
Note:
1. For HM700
• Applying this SOM is prohibited when USP V/VM
is used as an external subsystem and its external
volume is DP-VOL.
• Applying this SOM is recommended when the
above condition (1) is not met and SUN storage
is used as an external storage.
• Applying this SOM is recommended when the
above condition (1) is not met and EMC CX
series, VNX series or Fujitsu Fibre CAT CX series
is used as an external storage.
• Applying this SOM is recommended if the above
condition (1) is not met and a maintenance
operation such as firmware update causing
controller reboot is executed on the external
storage side while a storage system other than
Hitachi product is used as an external
subsystem.
2. While USP V/VM is used as an external subsystem
and its volume is DP-VOL, if some Pool-VOLs
constituting the DP-VOL are blocked, a phenomenon
of external path blockade and recovery occurs
repeatedly.
3. In the case that a virtual volume mapped by UVM is
set to pool-VOL and used as DP-VOL in local
subsystem, this SOM can be applied without
problem.
OFF -
Mode Category Description Default
MCU/
RCU