eG Monitoring
 

Measures reported by TPDSysStTest

The storage controller 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 storage controller can cause a marked deterioration in the overall performance of the storage sub-system, as it is indicative of severe deficiencies in the load-balancing algorithm that drives the storage controllers. Using the TPDSysStTest test, administrators can easily monitor the current state, usage, and load on each of the storage controllers on the Storage system, quickly detect an overload condition, precisely point to the storage controller that is bearing its brunt, and promptly initiate measures to resolve the issue, so as to ensure the optimal performance of the Storage system.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
operationalStatus Indicates the current operational state of this storage 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 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 controller. 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 controller.   This measure will be reported only if the API provides a detailed operational state.

Typically, the detailed state will describe why the storage controller is in a particular operational state. For instance, if the operationalStatus measure reports the value Stopping for a storage controller, then this measure will explain why that storage 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 storage controller. 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 controller. MB/Sec  
iops Indicates the rate at which I/O operations were performed on this storage controller. IOPS Compare the value of this measure across storage controllers to know which storage controllers 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 controllers.

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