Dell PowerVault MD3420 - Manual (Page 311)

Parameter Description
mediaScanRate The number of days over which the media scan
runs. Valid values are disabled, which turns off
the media scan, or 1 day to 30 days, where 1 day is
the fastest scan rate, and 30 days is the slowest
scan rate. A value other than disabled or 1 to 30
does not allow the media scan to function.
password The password for the storage array. Enclose the
password in double quotation marks (" ").
userRole Defines the user role for the password. The user
role can be either:
• admin – Enables you to view and modify
storage array configurations
• monitor – Enables you to view storage array
configurations and monitor storage array health
conditions, but not modify the configuration
The userRole parameter is optional. If you do
not use the userRole parameter, the storage array
uses any password that you define as the
administrator password.
userLabel The name for the storage array. Enclose the
storage array name in double quotation marks (" ").
isnsRegistration The means of listing the iSCSI target on the iSNS
server. Set the parameter to TRUE to list it.
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.
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