Dell Compellent Disks Test
This test monitors the current state, overall health, and the load-balancing capability of each disk in the Storage Center. With the help of this test, administrators can not only identify failed disks, but can also predict the potential failure of a disk, so that efforts can be undertaken to avert the same. In addition, the test also points administrators to disks that are handling more I/O requests than the rest, thus shedding light on irregularities in the distribution of I/O load across disks and prompting administrators to fine-tune the load-balancing algorithm. In addition, the test also proactively alerts administrators to probable slowdowns in I/O processing by specific disks, thereby enabling administrators to initiate pre-emptive actions.
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 disk on the Dell Compellent Storage Center.
Parameter | Description |
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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. |
Detailed Diagnosis |
To make diagnosis more efficient and accurate, the eG Enterprise system embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option against Detailed Diagnosis. To disable the capability, click on the Off option. The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:
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Measurement | Description | Measurement Unit | Interpretation | ||||||||||||||||||||||||||||||||||||||||
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Health state |
Indicates how healthy this disk currently is. |
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The values that this measure can report and their corresponding numeric values are discussed in the table below:
Note: By default, this measure reports the Measure Values discussed above to indicate the state of a disk. In the graph of this measure however, states are represented using the numeric equivalents only. The detailed diagnosis of this measure if enabled, lists the capacity of the disk. |
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Operational status |
Indicates the current operational state of this disk. |
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The values that this measure can report and their corresponding numeric values are discussed in the table below:
Note: By default, this measure reports the Measure Values discussed above to indicate the operational state of a disk. In the graph of this measure however, operational states are represented using the numeric equivalents only. |
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Detailed operational status |
Describes the current operational state of this disk. |
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Typically, the detailed state will describe why the disk is in a particular operational state. For instance, if the Operational status measure reports the value Stopping for a disk, then this measure will explain why that disk is being stopped. The values that this measure can report and their corresponding numeric values are discussed in the table below:
Note: By default, this measure reports the Measure Values discussed above to indicate the detailed operational state of a disk. In the graph of this measure however, detailed operational states are represented using the numeric equivalents only. |
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Data transmitted |
Indicates the rate at which data was transmitted by this disk. |
MB/Sec |
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IOPS |
Indicates the rate at which I/O operations were performed on this disk. |
IOPS |
Compare the value of this measure across disks to know which disk 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 disks. You may then want to take a look at the Reads and Writes measure to understand what to fine-tune – the load-balancing algorithm for read requests or that of the write requests. |
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Reads |
Indicates the rate at which read operations were performed on this disk. |
Reads/Sec |
Compare the value of this measure across disks to know which disk handled the maximum number of read requests and which handled the least. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across disks. |
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Writes |
Indicates the rate at which write operations were performed on this disk. |
Writes/Sec |
Compare the value of this measure across disks to know which disk handled the maximum number of write requests and which handled the least. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across disks. |
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Data reads |
Indicates the rate at which data is read from this disk. |
MB/Sec |
Compare the value of these measures across disks to identify the slowest disk in terms of servicing read and write requests (respectively). |
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Data writes |
Indicates the rate at which data is written to this disk. |
MB/Sec |
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Disk busy |
Indicates the percentage of time this disk was busy processing requests. |
Percent |
Compare the value of this measure across disks to know which disk was the busiest and which disk was not. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across disks. |
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Average read size |
Indicates the amount of data read from this disk per I/O operation |
MB/Op |
Compare the value of these measures across disks to identify the slowest disk in terms of servicing read and write requests (respectively). |
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Average write size |
Indicates the amount of data written to this disk per I/O operation. |
MB/Op |
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Read hits |
Indicates the percentage of read requests that were serviced by the cache of this disk. |
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 disk accesses, which are expensive operations, are high. |
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Write hits |
Indicates the percentage of write requests that were serviced by the cache of this disk. |
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 disk accesses, which are expensive operations, are high. |
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Average response time |
Indicates the time taken by this disk to respond to I/O requests. |
Microsecs |
Ideally, this value should be low. If not, it implies that the disk is slow. |
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Queue depth |
Indicates the number of requests that are in queue for this disk. |
Number |
A consistent increase in this value indicates a potential processing bottleneck with the disk. |