Hitachi Universal Storage Platform VM Computer Drive User Manual


 
Functional and Operational Characteristics 3-19
Hitachi Universal Storage Platform V/VM User and Reference Guide
Mode Category Function Default MCU/RCU
704
OPEN and
mainframe
To reduce the chance of MIH, this option can reduce the priority
of SI, VM, CoW Shapshot, Flash Copy or Resync copy internal
IO requests so that host IO has a higher priority. This mode
creates new work queues where these jobs can be assigned
with a lower priority.
Mode 704 = ON: Copy processing requested is registered into a
newly created queue so that the processing is scheduled with
lower priority than host I/O.
Mode 704 = OFF: Copy processing requested is not registered
into a newly created queue. Only the existing queue is used.
Note: If the PDEV is highly loaded, the priority of Read/Write
processing made by SI, VM, CoW Shapshot, Flash Copy or
Resync may become lower. As a consequence the copy speed
may be slower.
OFF –