How to configure and run QLogic Open-iSCSI on SLES11 SP2

This document (7008181) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 11 Service Pack 2

Situation

Open-iSCSI support has been added to the QLogic iSCSI driver in SUSE Linux Enterprise Server 11 Service Pack 2 (SLES11 SP2). This document provides a brief overview of how to configure and run the QLogic Open-iSCSI solution on SLES11 SP2.

Resolution

Open-iSCSI Infrastructure supports Discovery, Login, Logout to iSCSI targets and modification and display of iSCSI Configuration parameters. QLogic iSCSI driver provides persistence through Flash and Open-iSCSI nodes and sendtargets databases.

Discovery, Login and Logout
Prior to SLES11 SP2, discovery and login to iSCSI targets was hardware offloaded and managed by the QLogic iSCSI adapter firmware. In SLES11 SP2, the Open-iSCSI infrastructure allows system administrator to manage QLogic iSCSI target discovery and login through QLogic adapter. This provides the system administrator with a uniform and standard way to manage different vendor interfaces.

Boot Target Login
Open-iSCSI is enabled by default on SLES11 SP2 and login to boot targets is triggered by iscsiadm during installation.
NOTES:
1. Additional command line kernel parameter withiscsi=1 has to be passed before beginning the OS installation. Failing to pass the kernel parameter withiscsi=1 would not detect the iSCSI disks.
2. The modules qla3xxx and qlcnic should be loaded respectively for the 1G and 10G QLogic iSCSI initiator entries to appear in the iscsi-client via YaST.
The default behavior can be changed by setting driver parameter ql4xdisablesysfsboot=1, which disables exporting boot targets in Flash to sysfs and login to boot targets is done by the driver. The kernel parameter withiscsi=1 is not used when ql4xdisablesysfsboot=1.

Persistence through Flash and Open-iSCSI Database
Prior to SLES11 SP2, targets were persisted by saving the entries in Flash. In SLES11 SP2, targets managed by Open-iSCSI are persisted by saving them in the user space node and sendtarget persistent database.
For targets in Flash, auto-login is triggered by QLogic iSCSI driver and firmware. For targets saved in Open-iSCSI persistent database, iSCSI Daemon, iscsid, can be configured to automatically start discovery and login through the sendtargets and nodes persistent databases.

QLogic Application Limitation
The SLES11 SP2 QLogic inbox driver does not have support for QLogic applications iscli and qaucli. The QLogic iSCSI driver and firmware handle discovery and login to targets in flash, and also exports them to sysfs where it can be viewed from.
NOTE:
Target entries that have been made persistent in Flash on SLES11 SP2 cannot be managed by the Open-iSCSI iscsiadm interface. All newly added targets can be managed by Open-iSCSI.

Additional Information

Linux Open-iSCSI README: http://www.open-iscsi.org/docs/README

Release Notes for SUSE Linux Enterprise Server 11 SP2 for the kernel parameter
withiscsi=1: http://www.suse.com/releasenotes/x86_64/SUSE-SLES/11-SP2/

QLogic User’s Guide IOCTL to Open-iSCSI Interface: http://driverdownloads.qlogic.com/QLogicDriverDownloads_UI/NewSearchResult.aspx?resourceid=MgA4ADMAMQAzAA==&Search=&productid=MQAxADUANgA=&CategoryID=NwAwAA==&OperatingID=MQAyADUA

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