EMC Centera Cluster Capacity Test
An EMC Centera cluster consists of three or more hardware nodes. A single rack can hold up to 32 nodes to porvide upto 30.8 TB of raw capacity. Multiple racks can be configured as a single cluster, delivering up to 180 TB of usable storage. If the cluster lacks space, the data cannot be stored in the target storage system which may lead to critical data loss. To avoid this and to ensure peak performance of the cluster, it is mandatory to monitor the space utilization of the cluster periodically. The Cluster Capacity test helps administrators in this regard!
This test reports the space available for use in the cluster and space that is utilized in the cluster. By closely monitoring the space utilization of the cluster, administrators may be alerted to potential space crunch at the earliest before the users complain.
Target of the test : An EMC Centera storage system.
Agent deploying the test : A remote agent
Outputs of the test : One set of results for each cluster in the target storage system
| Parameter | Description |
|---|---|
|
Test period |
How often should the test be executed. |
|
Host |
The host for which the test is to be configured. |
|
Port |
The port number at which the specified host listens. By default, this is NULL. |
|
User and Password |
In order to monitor an EMC Centera Storage, the eG agent has to be configured with the credentials of a read only user. Specify the login credentials of such a user in the User and Password text boxes. |
|
Confirm Password |
Confirm the password by retyping it here. |
|
CerteraViewer JAR Path |
Path of CenteraViewer on agent host. CenteraViewer is installed along with CenteraCLI. By default the installation path is C:\Program Files\EMC\Centera\2_4\SystemOperator\lib\CenteraViewer.jar |
|
Timeout Seconds |
Specify the time duration (in seconds) beyond which this test should time out in the TIMEOUT text box. The default is 120 seconds. |
| Measurement | Description | Measurement Unit | Interpretation |
|---|---|---|---|
|
Number of nodes |
Indicates the total number of nodes in the cluster. |
Number |
Storage system should have adequate number of storage nodes to store the data and access nodes to allow quick and easy access to resources. |
|
Number of nodes with storage role |
Indicates the number of nodes in storage node role as opposed to access nodes. |
Number |
|
|
Total raw capacity |
Indicates the total raw capacity available in the cluster. This includes capacity required for system, audit etc. |
TB |
If the free raw capacity is low, there will be a shortage of available capacity for upcoming reads and writes which may lead to data loss. You should monitor these number to maintain/add new capacity as and when required. The percentage of capacity provides an idea of how much of capacity is used.
|
|
Used raw capacity |
Indicates the used capacity available in the cluster. This includes capacity required for system, audit etc. |
TB |
|
|
Free raw capacity |
Indicates the free capacity available in the cluster. This includes capacity required for system, audit etc. |
TB |
|
|
Free raw capacity |
Indicates the percentage of free capacity available to use out of total capacity. |
Percentage |
|
|
System buffer |
Indicates the buffer size for system reads and writes. |
TB |
You can adjust the buffer size to achieve optimal performance for system reads and writes. |
|
Regeneration buffer |
Indicates the buffer size used for regeneration. |
TB |
You can adjust the buffer size to achieve optimal performance for regeneration reads and writes after disk failure. |
|
Available Capacity |
Indicates the capacity available in the cluster for user data. |
TB |
|
|
Total Objects |
Indicates the total number of objects which can be stored in cluster. |
Number |
|
|
Used objects |
Indicates the total number of objects addresses which are already used. |
Number |
|
|
Free objects |
Indicates the number of objects addresses which are already used. |
Number |
|
|
Free object count |
Indicates the percentage of object addresses free to be used. |
Percentage |
|
|
System resources |
Indicates the total capacity allocated for system resources. |
TB |
|
|
Offline Capacity |
Indicates the storage capacity which is offline at the time of measurement. |
TB |
|
|
Spare Capacity |
Indicates the storage capacity which is spare. |
TB |
|
|
Used Capacity |
Indicates the storage capacity already used for user data. |
TB |
|
|
Audit Metadata |
Indicates the capacity in the cluster used for audit metadata. |
TB |
|
|
Protected user data |
Indicates the capacity overhead required for providing protection to user data against failures. |
TB |
|
