SDX Storage - Disks Test

To ensure peak performance of an SDX appliance, it needs to be sized with adequate physical disk resources. If not, then frequent disk space contention and I/O overloads will end up significantly degrading the performance of the appliance. To avoid this, administrators must closely track physical disk usage, proactively alert administrators to a potential disk space crunch or a disk I/O contention, and thus enable administrators to initiate corrective action.

This is exactly what the SDX Storage - Disks test does. This test auto-discovers the physical disks supported by the SDX appliance, and for each physical disk, reports the current capacity, space usage, and the I/O activity on that disk. In the process, the test points to the disks that are not sized commensurate to their usage. Based on the pointers provided by this test, administrators can then proceed to resize their storage.

Target of the test : A NetScaler SDX

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each physical disk on the target NetScaler SDX.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed

Host

The host for which the test is to be configured.

SDX Username and SDX Password

To monitor a NetScaler SDX device, the eG agent should be configured with the credentials of a user with read-only privileges to the target device. Specify the credentials of such a user in the SDX Username and SDX Password text boxes.

Confirm Password

Confirm the password by retyping it here.

SSL

The eG agent collects performance metrics by invoking NITRO (NetScaler Interface Through Restful interfaces and Objects) APIs on the target NetScaler SDX device. Typically, the NITRO APIs can be invoked through the HTTP or the HTTPS mode. By default, the eG agent invokes the NITRO APIs using the HTTPS mode. This is why, the SSL flag is set to Yes by default. If the target NetScaler SDX device is not SSL-enabled, then the NITRO APIs can be accessed through the HTTP mode only. In this case, set the SSL flag to No.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Disk size

Indicates the current capacity of this disk.

GB

 

Disk utilized

Indicates the amount of space in this disk that is utilized.

GB

A low value is desired for this measure.

Disk free

Indicates the amount of space in this disk that is currently unused.

GB

A high value is desired for this measure.

Disk usage

Indicates the percentage of space in this disk that is in use.

Percent

Compare the value of this measure across disks to know which disk is being used excessively.

Typically, a value close to 100% is a cause for concern, as it implies that the disk is running out of space. You may want to consider adding more storage resources to prevent a serious storage contention.

Transactions

Indicates the rate of transactions to this disk.

Transactions/Sec

This is a good indicator of the level of I/O activity on a disk.

Blocks read

Indicates the rate at which data blocks are read from this disk.

Reads/Sec

You can use this value to measure the rate of output from the disk.

Blocks written

Indicates the rate at which data blocks are written to this disk.

Writes/Sec

You can use this value to measure the rate of input from the disk.

Total blocks read and written

Indicates the rate at which I/O operations are performed on this disk.

Operations/Sec

This is a good indicator of the workload of a disk. Compare the value of this measure across disks to identify that disk that is experiencing an I/O overload.