Sun StorEdge[TM] Traffic Manager software: primary path automatic failback does not always happen

Asset ID:	1-72-1010947.1
Update Date:	2010-09-14
Keywords:

Solution Type Problem Resolution Sure

Solution 1010947.1 : Sun StorEdge[TM] Traffic Manager software: primary path automatic failback does not always happen

Related Items


Sun Storage T3 Array
 Sun Storage T3+ Array
 Sun Storage Traffic Manager Software

Related Categories


GCS>Sun Microsystems>Storage - Disk>Modular Disk - Other
 GCS>Sun Microsystems>Storage Software>Storage Resource Management

PreviouslyPublishedAs
215101

Symptoms
The Sun StorEdge[TM] Traffic Manager server software(previously known
as MPXIO) feature - Automatic Failback configuration, is enabled by setting the
variable, auto-failback, to "enable" in the file /kernel/drv/scsi_vhci.conf.

There are certain conditions however, such that Automatic Failback to Primary
will not happen automatically, even when it is set.

Resolution
Sun StorEdge[TM] Traffic Manager software: primary path automatic failback does not always happen

When there is a Fibre Channel path state change from OFFLINE to STANDBY,
on the Primary Path(on asymmetric configurations, such as a Sun StorEdge T3/T4
array partner pair and a Sun StorEdge 6120 array), automatic failover back to
primary path is initiated.

On the other hand, executing luxadm failover to Secondary path, does not mean
failback to primary is going to happen automatically. In this case FC path
Primary state changes from ONLINE to STANDBY, and therefore no failback
to primary happens. This is expected behaviour, as no hardware path
failure has occurred. Failover back to primary has to be initiated manually,
through the luxadm failover command.

    *** luxadm failover primary <pathname> ***

Below, are example messages, of when Fibre Channel Primary path comes back
online, after a hardware failure(from a Solaris[TM] Operating System
/var/adm/messages file):

Feb 22 12:09:47 f6800a-dom-a qlc: [ID 686697 kern.info] NOTICE: Qlogic qlc(1): Link ONLINE
Feb 22 12:09:48 f6800a-dom-a fp: [ID 517869 kern.warning] WARNING: fp(1): N_x
Port with D_ID=20000, PWWN=210100e08b24fb0e reappeared in fabric
Feb 22 12:09:48 f6800a-dom-a fp: [ID 517869 kern.warning] WARNING: fp(1): N_x
Port with D_ID=20500, PWWN=20030003ba27cf02 reappeared in fabric

    *** fp driver detected primary path is now back online ***

Feb 22 12:09:48 f6800a-dom-a scsi: [ID 243001 kern.info]     Target 0x20500:
Nonzero peripheral qualifier: Device type=0x1f Peripheral qual=0x1
Feb 22 12:09:48 f6800a-dom-a mpxio: [ID 669396 kern.info]
/scsi_vhci/ssd@g60003ba047ced00042182d6b0007ac43 (ssd36) multipath status:
optimal, path /ssm@0,0/pci@18,700000/pci@2/SUNW,qlc@5/fp@0,0 (fp1) to target
address: 20030003ba27cf02,10 is standby. Load balancing: round-robin
Feb 22 12:09:48 f6800a-dom-a scsi: [ID 243001 kern.info] /scsi_vhci (scsi_vhci0):
Feb 22 12:09:48 f6800a-dom-a    Initiating failover for device ssd (GUID
60003ba047ced00042182d6b0007ac43)

    *** mpxio automatic failover back to primary path is initiated ***

Feb 22 12:09:50 f6800a-dom-a scsi: [ID 243001 kern.info] /scsi_vhci (scsi_vhci0):
Feb 22 12:09:50 f6800a-dom-a    Failover operation completed successfully for
device ssd (GUID 60003ba047ced00042182d6b0007ac43): failed over from
secondary to primary
Feb 22 12:09:50 f6800a-dom-a scsi: [ID 243001 kern.info] /scsi_vhci (scsi_vhci0):
Feb 22 12:09:50 f6800a-dom-a    Auto failback operation succeeded for device ssd
(GUID 60003ba047ced00042182d6b0007ac43)

    *** auto failback completed successfully ***

Product
Sun StorageTek Traffic Manager 3.0 Software
Sun StorageTek Traffic Manager 4.4 Software
Sun StorageTek Traffic Manager 3.1 Software
Sun StorageTek 6120/6320 Controller Firmware 3.2
Sun StorageTek T3 Array
Sun StorageTek T3+ Array

Internal Comments
To enable auto-failback:

Solaris 8 OS requires patch 111412-10

Solaris 9 OS requires patch 113039-02

In Solaris 10 OS, auto-failback is enabled by default, see bug id 4994592

MPXIO, SSTM, SE6320, auto-failback, failback, T3, T4, 6120, failover
Previously Published As
80455

Change History
Date: 2005-03-03
User Name: 18392
Action: Approved
Comment: Added product names, trademarking, did some re-wording and bolding for clarity, corrected spelling, grammar.
Version: 3
Date: 2005-03-01
User Name: 18392
Action: Accept
Comment:
Version: 0
Date: 2005-03-01
User Name: 33935
Action: Approved
Comment: Pls proceed with publishing !!
Version: 0
Date: 2005-02-22
User Name: 33935
Action: Accept
Comment:
Version: 0
Date: 2005-02-22
User Name: 87953
Action: Approved
Comment: Pls review
Version: 0

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