Measures reported by UnityLUNTest
A logical unit number (LUN) is a unique identifier used to designate individual or collections of hard disk devices for address by a protocol associated with a SCSI, iSCSI, Fibre Channel (FC) or similar interface. LUNs are central to the management of block storage arrays shared over a storage area network (SAN). LUN errors, poor LUN cache usage, and abnormal I/O activity on the LUNs, if not promptly detected and resolved, can hence significantly degrade the performance of the target storage system. This is why, it is important that LUN performance is continuously monitored. This can be achieved using the UnityLUNTest test. This test auto-discovers the LUNs in the target storage system and reports the current state of each LUN and measures the level of I/O activity on every LUN, so that administrators are notified of LUN-related problems well before they impact storage system performance.
Outputs of the test : One set of results for each Storage Processor: LUN combination on the target storage system being monitored.
The measures made by this test are as follows:
| Measurement |
Description |
Measurement Unit |
Interpretation |
| healthStatus |
Indicates the current health of this LUN. |
|
The values reported by this measure and its numeric equivalents are mentioned in the table below:
| Measure value |
Numeric Value |
| Normal |
0 |
| Attention |
1 |
| Unknown |
2 |
| Degraded/Warning |
3 |
| Minor failure |
4 |
| Major failure |
5 |
| Critical failure |
6 |
| Non-recoverable error |
7 |
Note:
By default, this measure reports the Measure Values listed in the table above to indicate the current health of this LUN. The graph of this measure however is represented using the numeric equivalents only - 0 to 7.
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc.
|
| readBandwidth |
Indicates the maximum amount of data read from this LUN per second. |
MB/sec |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, read bandwidth, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgReadBandwidth |
Indicates the average amount of data read from this LUN per second. |
MB/sec |
|
| writeBandwidth |
Indicates the maximum amount of data written to this disk per second. |
MB/sec |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, write bandwidth, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgWriteBandwidth |
Indicates the average amount of data written to this LUN per second. |
MB/sec |
|
| readIOPS |
Indicates the maximum number of read operations performed on this LUN per second. |
IOPS |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, read IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgReadIOPS |
Indicates the average number of read operations performed on this disk per second. |
IOPS |
|
| writeIOPS |
Indicates the maximum number of write operations performed on this LUN per second. |
IOPS |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, write IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgWriteIOPS |
Indicates the average number of write operations performed on this LUN per second. |
IOPS |
|
| totalIOPS |
Indicates the total number of I/O operations performed on this disk per second. |
IOPS |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, total IOPS, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgTotalIOPS |
Indicates the average number of I/O operations performed on this LUN per second. |
IOPS |
|
| queueLength |
Indicates the maximum number of requests to this LUN that are in queue. |
IOPS |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, queue length, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgQueueLength |
Indicates the average number of requests to this LUN that are in queue. |
IOPS |
A very high value could indicate a processing bottleneck on the LUN. By comparing the value of this measure across LUNs, you can quickly identify which LUN has too many pending requests - this LUN could probably be the one with the processing bottleneck. |
| responseTime |
Indicates the maximum time taken by this LUN to respond to user requests. |
Milliseconds |
The detailed diagnosis of this measure lists the LUN ID, name of the storage processor, health, response time, the host accessing the LUN, thin provisioning, snapshot count, replication destination etc. |
| avgResponseTime |
Indicates the average time taken by this LUN to respond to user requests. |
Milliseconds |
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