IBM Support

Using iSCSI failover option in Linux - IBM BladeCenter

Troubleshooting


Problem

Trying to use the failover property on the iSCSI mapped LUNs, with two paths using multi-pathed, may fail when both the ethernet interfaces are configured with the same subnet mask. Even with multi-pathed driver running, while removing the ethernet linkfrom one interface, might fail the iSCSI mapped LUN instead of switching over to the other path. At that state, executing "multipath -ll" will result as below: sdb: checker msg is "readsector0 checker reports path is down" SCSI error - SCSI CDB: 0xc0 0x00 0x01 0x0a 0x98 0x0a 0x41 0x80 0x00 0x00 - masked_status=0x00, host_status=0x01, driver_status=0x00 SCSI error - SCSI CDB: 0x12 0x01 0xc1 0x00 0x80 0x00 - masked_status=0x00, host_status=0x01, driver_status=0x00 sde: checker msg is "readsector0 checkerreports path is down" SCSI error - SCSI CDB: 0xc0 0x00 0x01 0x0a 0x98 0x0a 0x41 0x80 0x00 0x00 - masked_status=0x00, host_status=0x01, driver_status=0x00 SCSI error - SCSI CDB: 0x12 0x01 0xc1 0x00 0x80 0x00 - masked_status=0x00, host_sta

Resolving The Problem

Source

RETAIN tip: H192167

Symptom

Trying to use the failover property on the iSCSI mapped LUNs, with two paths using multi-pathed, may fail when both the ethernet interfaces are configured with the same subnet mask.

Even with multi-pathed driver running, while removing the ethernet link from one interface, might fail the iSCSI mapped LUN instead of switching over to the other path.

At that state, executing "multipath -ll" will result as below:

sdb: checker msg is "readsector0 checker reports path is down" SCSI error
  • SCSI CDB: 0xc0 0x00 0x01 0x0a 0x98 0x0a 0x41 0x80 0x00 0x00
  • masked_status=0x00, host_status=0x01, driver_status=0x00 SCSI error
  • SCSI CDB: 0x12 0x01 0xc1 0x00 0x80 0x00
  • masked_status=0x00, host_status=0x01, driver_status=0x00 sde: checker msg is "readsector0 checker reports path is down" SCSI error
  • SCSI CDB: 0xc0 0x00 0x01 0x0a 0x98 0x0a 0x41 0x80 0x00 0x00
  • masked_status=0x00, host_status=0x01, driver_status=0x00 SCSI error
  • SCSI CDB: 0x12 0x01 0xc1 0x00 0x80 0x00
  • masked_status=0x00, host_status=0x01, driver_status=0x00 360a98000686f6a386134376850714e59dm-0 NETAPP,LUN size=2.0G features=1 queue_if_no_path hwhandler=0 \_ round-robin 0 prio=0 enabled \_ 1:0:0:0 sdb 8:16 failed faulty \_ 2:0:0:0 sde 8:64 failed faulty
Affected configurations

The system may be any of the following IBM servers:

  • BladeCenter Chassis, type 7967, any model
  • BladeCenter Chassis, type 8677, any model
  • BladeCenter H, type 7989, any model
  • BladeCenter H, type 8852, any model
  • BladeCenter JS21, type 7988, any model

The system is configured with one or more of the following IBM Options:

  • QLogic iSCSI Expansion Card for IBM eServer BladeCenter, Option 26K6487

The system is configured with at least one of the following:

  • SuSE Linux SLES 10, Service Pack 1

Note: This does not imply that the network operating system will work under all combinations of hardware and software.

Please see the compatibility page for more information:

http://www.ibm.com/servers/eserver/serverproven/compat/us/
Workaround

Configuring the ethernet interfaces, with different subnet mask, will help to exhibit the failover feature using the multi-pathed driver.

Document Location

Worldwide

Operating System

BladeCenter:SUSE Linux Enterprise Server 10

[{"Type":"HW","Business Unit":{"code":"BU016","label":"Multiple Vendor Support"},"Product":{"code":"HW20T","label":"BladeCenter E Chassis"},"Platform":[{"code":"PF047","label":"SurePOS"}],"Line of Business":{"code":"","label":""}},{"Type":"HW","Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"HW21X","label":"BladeCenter JS21 Blade"},"Platform":[{"code":"PF047","label":"SurePOS"}],"Line of Business":{"code":"LOB57","label":"Power"}},{"Type":"HW","Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"HW21Y","label":"BladeCenter H Chassis"},"Platform":[{"code":"PF047","label":"SurePOS"}],"Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
29 January 2019

UID

ibm1MIGR-5073425

Page Feedback