DELL 34XX User Manual

Page of 417
Parameter
Description
NOTE: No other command options can be 
used in conjunction with 
isnsRegistration.
Notes
When you use this command, you can specify one or more of the optional parameters.
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 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 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 cacheFlushStart parameter. For example, if the value of the 
cacheFlushStart parameter is set to 80, you may set the value of the cacheFlushStart 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.
Password
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