EMC Unity LUN Capacity Test

Thin provisioning, also known as virtual provisioning or thin storage, is an on-demand storage allocation based on user requirements in storage area networks (SAN), centralized storage disks, and storage virtualization systems.

In thin storage, as the user consumes their allocated storage space, they are allocated more. Alternatively, when they free up space, by deleting files or transferring data, the idle space is reclaimed, repurposed and used for other workloads in need of storage.

In comparison to thin provisioning, thick provisioning (also called fat provisioning) pre-allocates storage space in anticipation of future capacity requirements. While both thin and thick provisioning are methods of storage allocation, the difference lies in how the Logical Unit Number (LUN) is configured. A storage administrator should always be up to date with the LUN configuration in their environment as well as the capacity of the LUNs. To aid administrators in figuring out the capacity of thousands of LUNs in a much shorter duration, eG Enterprise offers the EMC Unity LUN Capacity test.

Using this test, administrators can figure out if the LUN is thin provisioned or not. Also, this test throws light on total capacity and the allocated capacity of each LUN. This way, administrators can figure out the LUN that is allocated with more storage resources. This test also helps administrators figure out the total capacity of each LUN in the storage pool.

Target of the test : An EMC Unity Storage System

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each Storage Processor: LUN combination on the target storage system being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the storage system for which this test is to be configured.
UniSphere CLI Path	The eG agent uses the command-line utility, UEMCli.exe, which is part of the UniSphere Management Suite, to communicate with and monitor the storage device. To enable the eG agent to invoke the CLI, configure the full path to the CLI here.
Username and Password	Provide the credentials of a user possessing 'monitor' role to access the storage system in the Username and Password text boxes.
Confirm Password	Confirm the Password by retyping it in the Confirm Password text box.
Timeout	Specify the duration (in seconds) beyond which this test should time out in the Timeout text box. The default is 300 seconds.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Is thin provisioning enabled?

Indicates whether/not thin provisioning is enabled for this LUN.

The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure value	Numeric Value
No	0
Yes	1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate whether/not thin provisioning is enabled on each LUN. The graph of this measure however is represented using the numeric equivalents only i.e., 0 or 1.

LUN size

Indicates the overall capacity of this LUN.

Allocated

Indicates the total storage capacity that is currently allocated to this LUN.

Compare the value of this measure across LUNs to figure out the LUN that is allocated with more storage capacity.

Unallocated

Indicates the amount of storage capacity that is yet to be allocated to this LUN.

Pool size used on this LUN

Indicates the total capacity of this LUN in the storage pool.

If the LUN is thin-provisioned, then, the value of this measure is the sum of Allocated measure, the Snapshot size used by the LUN and the Space used for metadata of the LUN.

If the LUN is not thin-provisoned, then , the value of this measure is the sum of total LUN size, Snapshot used by the LUN and the Space used for metadata of the LUN.