eG Monitoring
 

Measures reported by DelCmplSysStTest

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 DelCmplSysStTest 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.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
operationalStatus Indicates the current operational state of this storage processor.   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 Dormat
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 processor. In the graph of this measure however, operational states are represented using the numeric equivalents only.
detailedStatus Describes the current operational state of this storage processor.   Typically, the detailed state will describe why the storage processor is in a particular operational state. For instance, if the Operational status measure reports the value Stopping for a storage processor, then this measure will explain why that storage processor 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 storage processor. In the graph of this measure however, detailed operational states are represented using the numeric equivalents only.
dataTransmitted Indicates the rate at which data was transmitted by this storage processor. MB/Sec  
iops Indicates the rate at which I/O operations were performed on this storage processor. IOPS Compare the value of this measure across storage processors to know which storage processor 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 processors.

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.

reads Indicates the rate at which read operations were performed on this storage processor. Reads/Sec Compare the value of this measure across storage processors to know which storage processor 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 processor. Writes/Sec Compare the value of this measure across storage processors to know which storage processor handled the maximum number of write requests and which handled the least.
dataReads Indicates the rate at which data is read from this storage processor. MB/Sec Compare the value of these measures across storage processors to identify the slowest storage processor in terms of servicing read and write requests (respectively).
dataWritten Indicates the rate at which data is written to this storage processor. MB/Sec
avgReadSize Indicates the amount of data read from this storage processor per I/O operation. MB/Op Compare the value of these measures across storage processors to identify the slowest storage processor in terms of servicing read and write requests (respectively).
avgWriteSize Indicates the amount of data written to this storage processor per I/O operation. MB/Op
readHits Indicates the percentage of read requests that were serviced by the cache of this storage processor. 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 processor accesses, which are expensive operations, are high.
writeHits Indicates the percentage of write requests that were serviced by the cache of this storage processor. Percent