Dell PowerVault MD3620f Command Line Interface Manual page 255

Cache Flush Start and Cache Flush Stop
When you define values to start a cache flush, a value that is too low increases
the chance that data needed for a host read is not in the cache. A low value
also increases the number of physical disk writes that are necessary to
maintain the cache level, which increases system overhead and decreases
performance.
When setting storage array cache settings, the value of the cacheFlushStart
parameter must always be greater than or equal to the value of the
cacheFlushStop parameter. For example, if the value of the cacheFlushStart
parameter is set to 80, you may set the value of the cacheFlushStop
parameter within the range of 0 to 80.
When you define values to stop a cache flush, the lower the value, the higher
the chance that the data for a host read requires a physical disk read rather
than reading from the cache.
Default Host Type
When you define host types, if Storage Partitioning is enabled, the default
host type affects only those virtual disks that are mapped in the default group.
If Storage Partitioning is not enabled, all of the hosts that are attached to the
storage array must run the same operating system and be compatible with the
default host type.
Media Scan Rate
Media scan runs on all of the virtual disks in the storage array that have
optimal status, do not have modification operations in progress, and have the
mediaScanRate parameter enabled. Use the set virtualDisk command to
enable or disable the mediaScanRate parameter.
NOTE:
If you are using self-encrypting disk physical disks in your storage array,
you must use these criteria for your storage array password.
NOTE:
You must set a password for your storage array before you can create a
security key for encrypted self-encrypting disk physical disks.
Script Commands
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