eG Monitoring
 

Measures reported by DelCmplArrayTest

This test monitors the current state, overall health, and the load-balancing capability of each storage array in the Dell Compellent storage system. 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.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
operationalStatus 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 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 array. 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 array.   Typically, the detailed state will describe why the storage array is in a particular operational state. For instance, if the operationalStatus 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.

dataTransmitted 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.
dataReads 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).
dataWritten Indicates the rate at which data is written to this storage array. MB/Sec
avgReadSize 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).
avgWriteSize Indicates the amount of data written to this storage array per I/O operation. MB/Op
readHits 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.
writeHits 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.