Dell PowerVault MD3220 Cli Manual page 210

You can run the set storageArray autoSupportConfig command on more than
one storage array.
Cache Block Size
When you define cache block sizes, use the 4-KB cache block size for storage
arrays that require I/O streams that are typically small and random. Use the 8-
KB cache block size when the majority of your I/O streams are larger than 4
KB but smaller than 8 KB. Use the 16-KB cache block size or the 32-KB cache
block size for storage arrays that require large data transfer, sequential, or
high-bandwidth applications.
The cacheBlockSize parameter defines the supported cache block size for all
of the virtual disks in the storage array. Not all RAID controller module types
support all cache block sizes. For redundant configurations, this parameter
includes all of the virtual disks that are owned by both RAID controller
modules within the storage array.
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.
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Script Commands