Dell Compellent Controllers Test

The controller of the Dell Compellent Storage Center enables the administrator in serving the purpose of the following:

binding LUNs
execute CLI commands
perform read/write operations from external server to SAN

Excessive usage of or heavy I/O load on a single controller can cause deterioration in the overall performance of the storage center, as it is indicative of severe deficiencies in the load-balancing algorithm that drives the controllers. Using the Dell Compellent Controllers test, administrators can easily monitor the current state, usage, and load on each of the controller on the Storage Center, quickly detect an overload condition, precisely point to the controller that is overloaded, and promptly initiate measures to resolve the issue, so as to ensure the optimal performance of the Storage Center.

Target of the test : A Dell Compellent Storage Center

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each controller on the Dell Compellent Storage Center.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed
Host	The storage device for which the test is to be configured.
Port	The port number at which the specified storage device listens to. By default, this will be NULL.
User and Password	Specify the credentials of a user who has the right to execute API commands on the Dell Compellent Storage Center and pull out metrics. The specified user is the Pegasus CIM User who should possess Administator privileges and should be associated with the Logon as a Service policy.
Confirm Password	Confirm the password by retyping it here.
SSL	Set this flag to Yes, if the storage device being monitored is SSL-enabled.
CIM Server Port	The SMI–S provider of the Dell Compellent Storage Center provides access for monitoring and management via the HTTP and HTTPS protocols for CIM API request/response semantics. To enable the eG agent to access the SMI-S Provider, invoke the CIM API commands, and collect the required metrics, you need to specify the service port on the SMI- S provider in the CIM Server Port text box that listens for HTTP/HTTPS requests for CIM API semantics. By default, this is port 5988. If the service port on the SMI-S Provider listens only to HTTPS requests, then specify the port as 5989.
IsEmbedded	If this flag is set to True, it indicates that the SMI-S Provider is embedded on the Storage Center. On the other hand, if this flag is set to False, it indicates that the SMI-S Provider has been implemented as a proxy.
SerialNumber	If the SMI-S Provider has been implemented as a proxy, then such a provider can be configured to manage multiple Storage Centers. This is why, if the IsEmbedded flag is set to False, you will have to explicitly specify which Storage Center you want the eG agent to monitor. Since each Storage Center is uniquely identified by a serial number, specify the same in the SerialNumber text box.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Operational status

Indicates the current operational state of this controller.

The values that this measure can report and their corresponding numeric values are discussed in the table below:

Numeric Value	Measure Value
0	OK
1	In Service
2	Power Mode
3	Completed
4	Starting
5	Dormant
6	Other
7	Unknown
8	Stopping
9	Stressed
10	Stopped
11	Supporting Entity in Error
12	Degraded or Predicted Failure
13	Predictive Failure
14	Lost Communication
15	No Contact
16	Aborted
17	Error
18	Non-Recoverable Error

Note:

By default, this measure reports the Measure Values discussed above to indicate the operational state of a controller. In the graph of this measure however, operational states are represented using the numeric equivalents only.

Detailed operational status

Describes the current operational state of this controller.

Typically, the detailed state will describe why the controller is in a particular operational state. For instance, if the Operational status measure reports the value Stopping for a controller, then this measure will explain why that controller is being stopped.

The values that this measure can report and their corresponding numeric values are discussed in the table below:

Numeric Value	Measure Value
0	Online
1	Success
2	Power Saving Mode
3	Write Protected
4	Write Disabled
5	Not Ready
6	Removed
7	Rebooting
8	Offline
9	Failure

Note:

By default, this measure reports the Measure Values discussed above to indicate the detailed operational state of a controller. In the graph of this measure however, detailed operational states are represented using the numeric equivalents only.

Data transmitted

Indicates the rate at which data was transmitted by this controller.

MB/Sec

IOPS

Indicates the rate at which I/O operations were performed on this controller.

IOPS

Compare the value of this measure across controllers to know which controller handled the maximum number of I/O requests and which handled the least. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across controllers.

You may then want to take a look at the Reads and Writes measures to understand what to fine-tune – the load-balancing algorithm for read requests or that of the write requests.

Reads

Indicates the rate at which read operations were performed on this controller.

Reads/Sec

Compare the value of this measure across controllers to know which controller handled the maximum number of read requests and which handled the least.

Writes

Indicates the rate at which write operations were performed on this controller.

Writes/Sec

Compare the value of this measure across controllers to know which controller handled the maximum number of write requests and which handled the least.

Data reads

Indicates the rate at which data is read from this controller.

MB/Sec

Compare the value of these measures across controllers to identify the slowest controller in terms of servicing read and write requests (respectively).

Data writes

Indicates the rate at which data is written to this controller.

MB/Sec

Average read size

Indicates the amount of data read from this controller per I/O operation

MB/Op

Compare the value of these measures across controllers to identify the slowest controller in terms of servicing read and write requests (respectively).

Average write size

Indicates the amount of data written to this controller per I/O operation.

MB/Op

Read hits

Indicates the percentage of read requests that were serviced by the cache of this controller.

Percent

A high value is desired for this measure. A very low value is a cause for concern, as it indicates that cache usage is very poor; this in turn implies that direct controller accesses, which are expensive operations, are high.

Write hits

Indicates the percentage of write requests that were serviced by the cache of this controller.

Percent