Dell 32XX Performance Tuning, Synchronizing RAID Controller Module Clocks, Monitoring Performance

•Change or delete logical unit number (LUN) mappings on a virtual disk holding a reservation.

•Delete virtual disk groups or virtual disks that have any reservations.

To determine which virtual disks have reservations, run the following command:

show (allVirtualDisks virtualDisk [virtualDiskName] virtualDisks [virtualDiskName1

... virtualDiskNameN]) reservations

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	The RAID controller module in slot 0 or 1 and a
	Modules	list of the virtual disks owned by the RAID
		controller module.
	Virtual Disk	A list of the virtual disk names.
	Storage Array	A list of the totals for both RAID controller
	Totals	modules in an active-active RAID controller

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