VNXe LUN Test

A logical unit number (LUN) is a unique identifier used to designate individual or collections of hard disk devices for address by a protocol associated with a SCSI, iSCSI, Fibre Channel (FC) or similar interface. LUNs are central to the management of block storage arrays shared over a storage area network (SAN). LUN errors, poor LUN cache usage, and abnormal I/O activity on the LUNs, if not promptly detected and resolved, can hence significantly degrade the performance of the target storage system. This is why, it is important that LUN performance is continuously monitored. This can be achieved using the Vnxe LUN test. This test auto-discovers the LUNs in the target storage system and reports the current state of each LUN and measures the level of I/O activity on every LUN, so that administrators are notified of LUN-related problems well before they impact storage system performance.

Target of the test : An EMC VNXe 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
Parameters Description

Test Period

How often should the test be executed.

Host

The host for which the 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 in the UniSphere CLI Path text box.

Username and Password

Provide the credentials of a user possessing monitor role to access the storage device in the Username and Password text boxes.

Confirm Password

Confirm the password by retyping it here.

VNXe Version

Select the version of the target EMC VNXe storage system that is to be monitored from this list. By default, 1600 will be chosen from this list.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Health state

Indicates the current health of this LUN.

 

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

Measure value Numeric Value
Normal 0
Attention 1
Unknown 2
Degraded/Warning 3
Minor failure 4
Major failure 5
Critical failure 6
Non-recoverable error 7

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current health of this LUN. The graph of this measure however is represented using the numeric equivalents only - 0 to 7.

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Peak read bandwidth

Indicates the maximum amount of data read from this LUN per second.

MB/sec

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, read bandwidth, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average read bandwidth

Indicates the average amount of data read from this LUN per second.

MB/sec

 

Peak write bandwidth

Indicates the maximum amount of data written to this disk per second.

MB/sec

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, write bandwidth, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average write bandwidth

Indicates the average amount of data written to this LUN per second.

MB/sec

 

Peak read IOPS

Indicates the maximum number of read operations performed on this LUN per second.

IOPS

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, read IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average read IOPS

Indicates the average number of read operations performed on this disk per second.

IOPS

 

Peak write IOPS

Indicates the maximum number of write operations performed on this LUN per second.

IOPS

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, write IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average write IOPS

Indicates the average number of write operations performed on this LUN per second.

IOPS

 

Peak total IOPS

Indicates the total number of I/O operations performed on this disk per second.

IOPS

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, total IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average total IOPS

Indicates the average number of I/O operations performed on this LUN per second.

IOPS

 

Peak queue length

Indicates the maximum number of requests to this LUN that are in queue.

Number

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, queue length, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average queue length

Indicates the average number of requests to this LUN that are in queue.

Number

A very high value could indicate a processing bottleneck on the LUN. By comparing the value of this measure across LUNs, you can quickly identify which LUN has too many pending requests - this LUN could probably be the one with the processing bottleneck.

Peak response time

Indicates the maximum time taken by this LUN to respond to user requests.

Milliseconds

The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, response time, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.

Average response time

Indicates the average time taken by this LUN to respond to user requests.

Milliseconds