Specification changes other than new features in the version 4.5A00 of this software are as follows.
GDS 4.3A40 or earlier
Processing of synchronization copying invoked by hot spare does not affect the I/O performance of volume.
GDS 4.5A00 or later
When doing equivalent copy processing for the hot spare, compared to when equivalent copy processing is not done, the I/O performance of the volume is reduced by 10% on average when using root class and by 25% on average when using shared class or local class.
Set the following to maintain the I/O function of volume during the processing of synchronization copying invoked by hot spare. For cluster system, set the following on all nodes.
Change the value of spare_copy_delay (time delay in processing of synchronization copying invoked by hot spare) which is the GDS configuration parameter, to 50 milliseconds.
# sdxparam -S -p spare_copy_delay=50Add the following parameter to /kernel/drv/sfdsk.conf file, if not stated.
If the parameters are originally set, change only the value of the line that has been stated with the following:
SDX_SPARE_COPY_SZ=Second Edition8; SDX_SPARE_COPY_RANGE=16384;
Restart the system.
Note
Setting this will increase the time required in processing of synchronization copying invoked by hot spare.
The required time differs depending on the system, estimated required time before setting is about 2 min/1GB, after setting is 14 min/1GB.
Do not change the settings of SDX_SPARE_COPY_SZ and SDX_SPARE_COPY_RANGE other than the procedure described in this manual.