Node Disk Data Test

This test monitors the load balancing capability of each disk on each node of the target storage system. Using this test, administrators can pin point the disks that are handling more read and write operations than the rest. This way, irregularities in the distribution of I/O load across the disks can be detected at ease and in the process, administrators will be able to fine-tune the load-balancing algorithm.

Target of the test : An EMC Isilon Storage System

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each node:disk combination on the target storage system being monitored.

Measures are also reported for All descriptor.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The IP address of the host for which this test is to be configured.


The port at which the host listens. By default, this will be NULL.


Specify the time duration (in seconds) beyond which this test should time out in the Timeout text box. The default is 10 seconds.


By default, this parameter is set to No. This indicates that, by default, the eG agent will not require any special permissions to execute the commands. However, in some highly secure environments, this command cannot be executed directly as the eG agent install user is different from the root user who has the privileges to run all commands on the target storage system. In such cases, create a sudo user using the steps discussed in the Pre-requisites for Monitoring the EMC Isilon Storage System. Credentials of such a user should be specified in the Username and Password text boxes in the COMPONENTS page.

Set the Use Sudo parameter to Yes. This will enable the eG agent install user to execute the commands.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Data reads

Indicates the rate at which the data was read from this disk.


For the All descriptor, these measures will report the total amount of data read and written across the nodes per second.

Comparing the value of these measures across the disks will clearly indicate which disk drive is the busiest in terms of the rate at which data is read and written - it could also shed light on irregularities in load balancing across the disks.

Data writes

Indicates the rate at which the data was written on this disk.