Introduction
The Geneos Device IO Plug-in reports disk activity. This information is published by the kernel enabling the plug-in to produce highly accurate measures of throughput, utilisation, queue lengths, transaction rates, and service time. Each row in the table displays a device mounted on that disk.
The Device IO plug-in is only supported on and platforms.
On Netprobe versions 3.0.21 and up, the Device IO plug-in extracts its data from the operating system data sources file:
- DiskStats —
/proc/diskstats - SysFs —
/sys/block/<Device Name>/stat - Partitions —
/proc/partitions - StatFile —
/proc/stat
This plug-in extracts the data in order. For example, the Device IO plug-in looks for DiskStats first. If DiskStats is not available, then it looks for SysFs and so on.
Views (for a single view)
View (Solaris)
The Device IO produces a single view for Solaris as follows:
Table Legend
| Name | Description |
|---|---|
| Device | The name of the actual device |
| readRate | Reads per second |
| writeRate | Writes per second |
| readRateKB | KB read per second |
| writeRateKB | KB written per second |
| aveTransWaiting | average number of transactions waiting for service(queue length) |
| aveTransActive | average number of transactions actively being serviced (removed from the queue but not yet completed) |
| aveServiceTimeMs | average service time, in milliseconds |
| percentWait | percent of time there are transactions waiting for service (queue non-empty) |
| percentBusy | percent of time the disk is busy (transactions in progress) |
View (Linux)
The Device IO plug-in produces the following view for Linux:
Headline Legend
| Name | Description |
|---|---|
| activeSegments | The number of devices. |
Table Legend
| Name | Description |
|---|---|
| device | The name of the actual device. |
| readRate | The number of read requests that were issued to the device per second. |
| writeRate | The number of write requests that were issued to the device per second. |
| readRateSector | The number of sectors read from the device per second. |
| writeRateSector | The number of sectors written to the device per second. |
| aveRequestSize | Average size (in sectors) of the request that were issued to the device. |
| aveQueueLen | The average queue length of the requests that were issued to the device. |
| aveRequestTimeMs | The average time (in milliseconds) for I/O requests issued to the device to be served. |
| aveServiceTimeMs | The average service time (in milliseconds) for I/O requests that were issued to the device. |
| cpuUtilisation |
Percentage of CPU time during which requests were issued to the device. On Netprobe version 4.x.x or higher, the
Where:
|