Dell 36XX, 34XX, 38XX, 32XX manual Changing RAID Levels, Changing Segment Size

Type of Information	Description
	module pair, regardless if one, both, or neither
	are selected for monitoring
Total I/Os	Number of total I/Os performed since the storage array was started
Read Percentage	Percentage of total I/Os that are read operations (calculate the write
	percentage by subtracting the read percentage from 100 percent)
Cache Hit Percentage	Percentage of reads that are fulfilled by data from the cache rather
	than requiring an actual read from a physical disk
Current KB/second	Current transfer rate in kilobytes per second (current means the
	number of kilobytes per second since the last time the polling interval
	elapsed, causing an update to occur)
Maximum KB/second	Highest data transfer value achieved in the current kilobyte-per-
	second statistic block
Current IO/second	Current number of I/Os per second (current means the number of
	I/Os per second since the last time the polling interval elapsed,
	causing an update to occur)
Maximum IO/second	Highest number of I/Os achieved in the current I/O-per-second
	statistic block

The general form of the command is:

save storageArray performanceStats file="filename"

where, file is the name of the file in which you want to save the performance statistics. You can use any file name your operating system can support. The default file type is .csv. The performance information is saved as a comma-delimited file.

Before using the save storageArray performanceStats command, run the set session performanceMonitorInterval and set session performanceMonitorIterations commands to specify how often statistics are collected.

Changing RAID Levels

When creating a disk group, define the RAID level for the virtual disks in that group. You can later change the RAID level to improve performance or provide more secure protection for your data. To change the RAID level, run the following command:

set diskGroup [diskGroupNumber] raidLevel=(0156)

where, diskGroupNumber is the number of the disk group for which to change the RAID level.

Changing Segment Size

When creating a new virtual disk, define the segment size for that virtual disk. You can later change the segment size to optimize performance. In a multi-user database or file system storage environment, set your segment size to minimize the number of physical disks needed to satisfy an I/O request. Use larger values for the segment size. Using a single physical disk for a single request leaves other disks available to simultaneously service other requests. If the virtual disk is in a single-user large I/O environment,

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