User guide

System option modes B–13
Hitachi Unified Storage VM Block Module Hardware User Guide
696 Open This mode is available to enable or disable the QoS
function.
Mode 696 = ON:
QoS is enabled. (In accordance with the Share value set
to SM, I/Os are scheduled. The Share value setting from
RMLIB is accepted)
Mode 696 = OFF (default):
QoS is disabled. (The Share value set to SM is cleared. I/
O scheduling is stopped. The Share value setting from
host is rejected)
Note:
1. Set this mode to ON when you want to enable the QoS
function.
OFF .
701 Universal
Volume
Manager
Issues the Read command at the logical unit discovery
operation using UVM.
Mode 701 = ON: The Read command is issued at the
logical unit discovery operation.
Mode 701 = OFF: The Read command is not issued at the
logical unit discovery operation.
Notes:
1. When the Open LDEV Guard attribute (VMA) is
defined on an external device, set the system option
to ON.
2. When this option is set to ON, it takes longer time to
complete the logical unit discovery. The amount of
time depends on external storages.
3. With this system option OFF, if searching for external
devices with VMA set, the VMA information cannot be
read.
4. When the mode is set to ON while the following
conditions are met, the external volume is blocked.
a. RAID700 70-03-3x-00/00 or higher version is
used on the storage system.
b. An external volume to which Nondisruptive
Migration (NDM) attribute is set exists.
c. The external volume is reserved by the host
5. As the VMA information is USP/NSC specific, this
mode does not need to be ON when the external
storage is other than USP/NSC.
6. Set the mode to OFF when the following conditions
are met.
a. RAID700 70-03-3x-00/00 or higher version is
used on the storage system
b. An external volume to which Nondisruptive
Migration (NDM) attribute is set exists.
OFF .
Mode Category Description Default
MCU/
RCU