DELL 34XX User Manual

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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=(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, 
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