Dell PowerVault MD3260i - Manual (Page 111)

Type of Information Description
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=(0|1|5|6)
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, performance is maximized when a single I/O request is serviced with a single
data stripe; use smaller values for the segment size. To change the segment size, run the following command:
set virtualDisk ([virtualDiskName] | <wwid>)
segmentSize=segmentSizeValue
where, segmentSizeValue is the new segment size you want to set. Valid segment size values are 8, 16, 32, 64, 128,
256, and 512. You can identify the virtual disk by name or World Wide Identifier (WWID) (see Set Virtual Disk).
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