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Oracle® ZFS Storage Appliance Analytics Guide, Release OS8.7.x

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Updated: August 2017

Protocol: Fibre Channel Operations

This statistic shows Fibre Channel operations/sec (FC IOPS) requested by initiators to the appliance. Various useful breakdowns are available: to show the initiator, target, type and latency of the FC I/O.


See Protocol: iSCSI Operations for an example of a similar statistic with similar breakdowns.

When to Check Fibre Channel Operations

Fibre Channel operations/sec can be used as an indication of FC load, and can also be viewed on the dashboard.

Use the latency breakdown when investigating FC performance issues, especially to quantify the magnitude of the issue. This measures the I/O latency component for which the appliance is responsible for, and displays it as a heat map so that the overall latency pattern can be seen, along with outliers. If the FC latency is high, drill down further on latency to identify the client initiator, the type of operation and LUN for the high latency, and, check other statistics for both CPU and Disk load to investigate why the appliance is slow to respond; if latency is low, the appliance is performing quickly, and any performance issues experienced on the client initiator are more likely to be caused by other factors in the environment: such as the network infrastructure, and CPU load on the client itself.

The best way to improve performance is to eliminate unnecessary work, which may be identified through the client initiator, lun and command breakdowns.

Fibre Channel Operations Breakdowns

Table 38  Breakdowns of Fibre Channel Operations
Fibre Channel client initiator
Local SCSI target
The project for this FC request.
The LUN for this FC request.
type of operation
FC operation type. This shows how the SCSI command is transported by the FC protocol, which can give an idea to the nature of the I/O.
SCSI command sent by the FC protocol. This can show the real nature of the requested I/O (read/write/sync-cache/...).
A heat map showing the latency of FC I/O, as measured from when the FC request arrived on the appliance from the network, to when the response is sent; this latency includes the time to process the FC request, and to perform any disk I/O.
A heat map showing the file offset of FC I/O. This can be used to identify random or sequential FC IOPS. Use the Disk I/O operations statistic to check whether random FC IOPS maps to random Disk IOPS after the LUN and RAID configuration has been applied.
A heat map showing the distribution of FC I/O sizes.

These breakdowns can be combined to produce powerful statistics. For example, use "Protocol: Fibre Channel operations per second of command read broken down by latency" to examine latency for SCSI reads only.

Further Analysis

See Protocol: Fibre Channel Bytes for the throughput of this FC I/O; also see Cache: ARC Accesses to learn how well an FC read workload is returning from cache, and Disk: I/O Operations for the back-end disk I/O caused.