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EMS reports Link break detected on FC port due to faulty storage end SFP

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Applies to

  • ONTAP 9
  • Small form-factor pluggable(SFP)
  • Cisco Switch

Issue

  • EMS log reports Link flap events on Fibre Channel target adapter:

Thu May 25 01:23:26 AEST [Netapp: fct_tpd_work_thread_0: scsitarget.ispfct.linkBreak:error]: Link break detected on Fibre Channel target adapter 0e. Firmware status code status1 0x2, status2 0x7, and status4 0x0.
Thu May 25 01:30:08 AEST [Netapp: fct_tpd_work_thread_0: scsitarget.hwpfct.linkUp:notice]: Link up on Fibre Channel target adapter 0e.

  • FC target port status shows as online under sysconfig -a:

slot 0: Fibre Channel Target Host Adapter 0e
               (QLogic 8324 (8362) rev. 2, <ONLINE>)
               Firmware rev:      8.7.0
               Flash rev:         7.0.3
               Host Port Addr:    ae0700
               FC Nodename:       50:0a:09:80:80:84:xy:xx (500axxxxxxxxxxxx)
               FC Portname:       50:0a:09:81:80:84:yx:yy (500axxxxxxxxxxxx)
               Connection:        PTP, Fabric
               Switch Port:       sw:1/8
              SFP Vendor Name:  AVAGO
              SFP Vendor P/N:   AFBR-57F5MZ-NA3
              SFP Vendor Rev:   01
              SFP Serial No.:   AC1804Jxxxx
              SFP Connector:    LC
              SFP Capabilities: 4, 8, 16 Gbit/S

  • FC target port shows link disconnected under sysconfig -a 

slot 0: Fibre Channel Target Host Adapter 0d
                (QLogic 8324 (8362) rev. 2, <LINK DISCONNECTED>)
                Firmware rev:      8.9.0
                Flash rev:         7.0.3
                Host Port Addr:    000000
                FC Nodename:       50:0a:09:80:80:84:xy:xx (500axxxxxxxxxxxx)
                FC Portname:       50:0a:09:80:80:84:xy:xx (500axxxxxxxxxxxx)
                Connection:        No link
                Switch Port:       Unknown
            SFP Vendor Name:   FINISAR CORP.
            SFP Vendor P/N:    FTLF8529P4BCVAN1
            SFP Vendor Rev:    A
            SFP Serial No.:    P17BX7G
            SFP Connector:     LC
            SFP Capabilities:  4, 8, 16 Gbit/Sec

  • Rx and Tx power are in the optimal range as per fcp-adapter.xml log.
  • On Cisco switch connected to the affected port, switch port Tx power is showing as NA.

[2023-05-31 17:09:33] Tx Power N/A -- 1.70 dBm -13.00 dBm -1.30 dBm -9.00 dBm
[2023-05-31 17:09:33] Rx Power -2.19 dBm 3.00 dBm -15.90 dBm 0.00 dBm -11.90 dBm

  • Switch port is in error disabled state as per show int brief log and ITW errors being generated for the switch port under show interface counters:

show int brief-

 fc1/8 is down (Error disabled - bit error rate too high)

show interface counters-

[2023-05-31 17:09:32]  System Errorcode  : 0x4042001e MAC Bit error exceeded threshold
[2023-05-31 17:09:32]  Error Type        : Warning
[2023-05-31 17:09:32]  PhyPortLayer      : Fibre Channel
[2023-05-31 17:09:32]  Port(s) Affected  : fc1/8
[2023-05-31 17:09:32]  Error Description : MAC Bit error exceeded threshold [ITW]

  •  We could see entries of port flapping on switch port under show logging log:

[2023-05-31 17:09:40]  2023 May 22 09:42:24 sw %PORT-5-IF_DOWN_ADMIN_DOWN: %$VSAN 10%$ Interface fc1/8 is down (Administratively down)  CS1A-naclu01-02_e0e
[2023-05-31 17:09:40]  2023 May 22 09:42:27 sw %PORT-5-IF_UP: %$VSAN 10%$ Interface fc1/8 is up in mode F  CS1A-naclu01-02_e0e
023 May 25 01:29:55 sw %PORT-5-IF_DOWN_ADMIN_DOWN: %$VSAN 10%$ Interface fc1/8 is down (Administratively down) xxxx
[2023-05-31 17:09:40]  2023 May 25 01:30:08 sw %PORT-5-IF_UP: %$VSAN 10%$ Interface fc1/8 is up in mode F  xxxx

  • Below steps can be implemented to isolate the issue further:

  1. Reseat the cable/sfp on storage and switch port.

  2. Perform end to end cable testing including the patch panel , replace the cable if its faulty.

  3. If cable is not faulty, replace the SFP at switch end first as Tx power is NA.

Note: To isolate that switch port is not an issue cable can be moved to unused/free port on the switch end and see if link is coming up.

  1. If issue persists , storage end sfp will be replaced in that case.

 

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