Sun Storage 7000 Unified Storage System: Host Can Lose Fibre Channel Connectivity During Failbacks and Takeovers.

Asset ID:	1-72-1633658.1
Update Date:	2014-04-24
Keywords:

Solution Type Problem Resolution Sure

Solution 1633658.1 : Sun Storage 7000 Unified Storage System: Host Can Lose Fibre Channel Connectivity During Failbacks and Takeovers.

Applies to:

Sun ZFS Storage 7320 - Version All Versions to Not Applicable [Release All Releases to N/A]
Sun ZFS Storage 7420 - Version All Versions to Not Applicable [Release All Releases to N/A]
Sun ZFS Storage 7120 - Version All Versions to Not Applicable [Release All Releases to N/A]
7000 Appliance OS (Fishworks)

Symptoms

The host can occasionally lose connectivity to the FC luns presented by the appliance running 2011.04.24.6.0,1-1.36 firmware.

Feb 21 08:02:58 xxxx qlc: [ID 439991 kern.info] NOTICE: Qlogic qlc(3,0): Loop OFFLINE

Changes

This would happen after a failback or takeover on the appliance.

Cause

To ensure connectivity to the backend FC luns, the Fibre Channel ports on the appliance require to be listed as "Target"

zs3-4-node1:configuration san fc targets> show
Properties:
                       targets = wwn.21000024FF4E7EEC,wwn.21000024FF4E7EED,wwn.2100000E1E125810,wwn.2100000E1E125811

Targets:

NAME       MODE       WWN                     PORT                 SPEED
target-000 target     wwn.21000024FF4E7EEC    PCIe 9: Port 1       0 Gbit/s
target-001 target     wwn.21000024FF4E7EED    PCIe 9: Port 2       0 Gbit/s
target-002 target     wwn.2100000E1E125810    PCIe 7: Port 1       0 Gbit/s
target-003 target     wwn.2100000E1E125811    PCIe 7: Port 2       0 Gbit/s

Children:
                           groups => Manage groups

If the MODE is seen as "Initiator", the host will loose connectivity to the FC luns.

For example:

ss7320-node2:configuration san fc targets> show
Properties:
                       targets =

Targets:

NAME       MODE       WWN                     PORT                 SPEED
target-000 initiator wwn.21000024FF2E4EC6    PCIe 0: Port 1       2 Gbit/s
target-001 initiator wwn.21000024FF2E4EC7    PCIe 0: Port 2       2 Gbit/s

Children:
                           groups => Manage groups

There have been a few bugs in the 2011.x appliance f/w which may cause the ports to change their mode from "Target" to "Initiator".

BUG 15618238 - SUNBT6920713 FC: Win2k8 - 3 of 4 paths discovered after failover/failback of cluster heads.
Bug 15603587 - SUNBT6901282 FC: Win2k8 - MS MPIO - Incorrect number of paths discovered after failover/failback of cluster head
Bug 15619396 - SUNBT6922240 FC: OpenSolaris sometimes loses path after cluster failover/failback of cluster head.

Solution

2013 release of the appliance f/w resolved the issue.

The release notes state:

Release Note RN010
Title Some FC paths may not be rediscovered after takeover/failback
Platforms All
Related Bug IDs 15618238

It also states:

SAN - FC ports now default to target mode

Fibre channel ports now default to target mode, which is the more common requirement. A mode change continues to require a reboot for effect. If the appliance is connected to a tape SAN for backup, one or more of the FC ports will need to be switched to initiator mode and the system rebooted for effect.

This solution unfortunately does not apply to the 7x10 series since the 2013 release does not apply to the 7x10 series.

Hence for 7x10 boxes, the mode requires to be changed manually.

References

<BUG:15618238> - SUNBT6920713 FC: WIN2K8 - 3 OF 4 PATHS DISCOVERED AFTER FAILOVER/FAILBACK OF CLU
<BUG:18291810> - NAS ARRAY SIDE FC-HBA PORT INTERMITTENTLY CHANGES FROM TARGET TO INITIATOR
<NOTE:1434184.1> - Sun Storage 7000 Unified Storage System: How to Troubleshoot Fibre-Channel Problems

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