Administrator Guide

Flow Vision Administrator’s Guide 53

53-1002999-01

Troubleshooting using Flow Mirror

The following use cases describe how to use Flow Mirror to troubleshoot typical fabric performance

problems.

Using Flow Mirror to diagnose SCSI reserve and SCSI release

performance

If there is excessive SCSI reserve and release activity in a virtualized environment, you can use

Flow Mirror to identify the affected LUNs.The following example creates a flow to mirror all the SCSI

release frames from multiple servers to LUNs on the target on port 1/20. You can then analyze the

mirrored frames to determine the impacted LUNs.

switch:admin> flow --create flow_scsi -feature mirror –egrport 1/20 –srcdev “*” -dstdev “*”

-frametype scsiresrel

---------------------------------------------------------------------------------------------------------

| SID(*) | DID(*) | OXID | RXID | SOF | EOF | Frame_type | LUN(*) | Dir | Time-Stamp |

---------------------------------------------------------------------------------------------------------

| b28600 | a2bd00 | 0f27 | ffff | SOFi3 | EOFt | SCSI3_Rel | 0003 | Tx | Jul 16 17:21:47:253 |

| b28000 | a2bd00 | 09de | ffff | SOFi3 | EOFt | SCSI3_Rel | 0002 | Tx | Jul 16 17:21:47:253 |

| b2c680 | a2bd00 | 0afe | ffff | SOFi3 | EOFt | SCSI3_Rel | 0001 | Tx | Jul 16 17:21:47:253 |

| b28600 | a2bd00 | 0f51 | ffff | SOFi3 | EOFt | SCSI3_Rel | 0005 | Tx | Jul 16 17:21:47:253 |

| b28000 | a2bd00 | 09f0 | ffff | SOFi3 | EOFt | SCSI3_Res | 0002 | Tx | Jul 16 17:21:47:253 |

| b28600 | a2bd00 | 0f1f | ffff | SOFi3 | EOFt | SCSI3_Rel | 0004 | Tx | Jul 16 17:21:47:253 |

(output truncated)

Using Flow Mirror to troubleshoot protocol errors

You can use Flow Mirror to mirror protocol error frames. The following example mirrors only ABTS

frames egressing through port 1/20 to identify the ABTS protocol condition. The Flow Mirror output

provides you with samples of the ABTS frames for detailed analysis.

switch:admin> flow --create flow_protocol -feature mirror –egrport 1/20 –srcdev “*” –dstdev “*”

-frametype abts

NOTE

This can also be set up to mirror frames based on the total ABTS count provided by Flow Monitor.

Using Flow Mirror to diagnose a slow-draining F_Port

The following example creates a flow to mirror traffic passing in both directions from device

0x010200 to F_Port 15 on device 0x040500, and then displays the output. The collected frame

data may help you diagnose the slow-draining device. Figure 11 provides a diagram of what is

happening in this example.