The zero data page reclamation is performed.
See the system option mode 930 sheet for relationship with
system option mode 755.
Notes:
(1) The mode is applied when stopping or disabling zero
data page reclamation by user request is required.
(2) When the mode is set to ON, the zero data page
reclamation does not work at all.
* Zero data page reclamation by Write Same and UNMAP,
and IO synchronous page reclamation can work.
(3) When downgrading micro-program to a version that
does not support the mode while the mode is set to ON, set
the mode to OFF after the downgrade.
* Because the zero data page reclamation does not work at
all while the mode is set to ON.
937
By setting the mode to ON, DT monitoring data is collected
even if the pool is a DP pool.
Mode 937 = ON:
DT monitoring data is collected even if the pool is a DP pool.
Only Manual execution mode and Period mode are
supported.
Mode 937 = OFF:
DT monitoring data is not collected if the pool is a DP pool
Notes:
1. The mode is applied when DT monitoring data collection
is required in DP environment.
2. When DT is already used, do not set the mode to ON.
3. For DT monitoring data collection, shared memory for DT
must be installed. For details, see the system option mode
937 sheet.
4. If monitoring data collection is performed without shared
memory for DT installed, an error is reported and the
monitoring data collection fails.
5. Before removing the shared memory for DT, set the mode
to OFF and wait for 30 minutes.
6. Tier relocation with monitoring data collected when the
mode is set to ON is disabled.
7. When DP is converted into DT (after purchase of PP
license), the collected monitoring data is discarded.
8. Before downgrading the micro-program to an
unsupported version, set system option mode 937 to OFF
and wait for at least 30 minutes.
OFF
80 System option modes
Hitachi Virtual Storage Platform G800 Hardware Reference Guide