EMC ECS VDC Node Re-BalacingTest

When additional nodes are added into a configuration to upgrade capacity, ECS re-distributes erasure-coded chunks in the background, this process is called rebalancing. Although this doesn’t impact system performance, there is an increase in inter-node traffic. Rebalancing enhances local protection by leveraging all the resources within the infrastructure.

The purpose of this test is to ensure that the rebalancing process is working efficiently. This test collects metrics around rebalancing like if rebalancing is enabled and how much data is being rebalanced. Looking at these insights, administrators can understand what the impact on the system is of adding new nodes and the system is efficiently redistributing the data. If there is any issue or if any metrics are showing an abnormal number, administrators can take corrective actions.

Target of the test : A Dell EMC Elastic Cloud Storage System

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each Virtual Data Centre (VDC)

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed .


The host for which the test is to be configured. Since the storage device is managed using the IP address of its storage controller, the same will be displayed as host.


The port number at which the specified host listens. By default, this is NULL.


This is the port at which REST API connectivity is provided. By default, port 4443 is used.

Username and Password

To collect performance metrics from the target storage device, the eG agent should be configured with the credentials of a user who is vested with "read-only" privileges to access REST API of the target storage device. Specify the credentials of such a user in the Username and Password text boxes.

Confirm Password

Confirm the password by retyping it here.

Timeout Seconds

Specify the time duration for which this test should wait for a response from the storage system in the Timeout text box. By default, this is 60 seconds.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Is rebalancing enabled?

Indicates if the rebalancing is enabled or not



Pending rebalancing

Indicates the amount of data that is in the rebalance queue but has not been rebalanced yet.



Data rebalanced

Indicates the amount that has been rebalanced.