Dell PowerVault MD3260i - Manual (Page 110)

To clear persistent virtual disk reservations, run the following command:
clear (allVirtualDisks |
virtualDisk[virtualDiskName] | virtualDisks
[virtualDiskName1" ... "virtualDiskNameN])reservations
Synchronizing RAID Controller Module Clocks
To synchronize the clocks on both RAID controller modules in a storage array with the host clock, run the following
command:
set storageArray time
Locating Physical Disks
At times, you might need to locate a specific physical disk. In very large storage array configurations, this can
sometimes be awkward. If you need to locate a specific physical disk, turn on the indicator LED on the front of the
physical disk. To turn on the indicator LED on a physical disk, run the following command:
Performance Tuning
Over time, as a storage array exchanges data between the hosts and physical disks, its performance can degrade.
Monitor the performance of a storage array and make adjustments to the storage array operational settings to improve
performance.
Monitoring Performance
Monitor the performance of a storage array by using the save storageArray performanceStats command.
This command saves performance information to a file that you can review to determine how well the storage array is
running. The following table lists the performance information saved to the file.
Table 14. Storage Array Performance Information
Type of Information Description
Devices Devices are:
RAID Controller
Modules The RAID controller module in slot 0 or 1 and a list of
the virtual disks owned by the RAID controller module.
Virtual Disk A list of the virtual disk names.
Storage Array
Totals A list of the totals for both RAID controller modules in
an active-active RAID controller 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
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