(a) HUS VM 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) HUS VM is used on the storage system.
(b) An external volume to which Nondisruptive Migration
(NDM) attribute is set exists.
704
To reduce the chance of MIH, this option can reduce the
priority of SI, VM, CoW Snapshot, 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 Snapshot, Flash Copy or
Resync may become lower. As a consequence the copy
speed may be slower
N/A
721
When a parity group is uninstalled or installed, the following
operation is performed accordingly.
Mode 721 = ON:
When a parity group is uninstalled or installed, neither the
LED of the HDD for uninstallation lights up, nor the
instruction message for removing the HDD appears. Also,
the windows other than that of parity group, such as DKA or
DKU, are unavailable to select.
Mode 721 = OFF:
When a parity group is uninstalled or installed, the
operation is as before; the LED of the HDD lights up, and
the HDD must be unmounted and remounted.
Notes:
1. When the RAID level or emulation type is changed for the
existing parity group, this option should be applied only if
OFF
System option modes 65
Hitachi Virtual Storage Platform G800 Hardware Reference Guide
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