Dell Compellent Arrays Test

This test monitors the current state, overall health, and the load-balancing capability of each storage array in the Dell Compellent Storage Center. With the help of this test, administrators can be proactively alerted to potential array failures / slowdowns / overload conditions. This way, irregularities in the distribution of I/O load across arrays comes to light, prompting administrators to fine-tune the load-balancing algorithm.

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 storage array 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 storage array.

 

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 storage array. 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 storage array.

 

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

MB/Sec

 

IOPS

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

IOPS

Compare the value of this measure across storage arrays to know which storage array 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 storage arrays.

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 storage array.

Reads/Sec

Compare the value of this measure across storage arrays to know which storage array handled the maximum number of read requests and which handled the least.

Writes

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

Writes/Sec

Compare the value of this measure across storage arrays to know which storage array handled the maximum number of write requests and which handled the least.

Data reads

Indicates the rate at which data is read from this storage array.

MB/Sec

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

Data writes

Indicates the rate at which data is written to this storage array.

MB/Sec

Read hits

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

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 storage array accesses, which are expensive operations, are high.

Write hits

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

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 storage array accesses, which are resource-intensive operations, are high.

Average read size

Indicates the amount of data read from this storage array per I/O operation.

MB/Op

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

Average write size

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

MB/Op