The purpose of this discussion is to establish the scope of what will be delivered in the next release of OpenSolaris installer with regard to iSCSI boot.
In short, OpenSolaris could be installed on a remote iSCSI disk on a SAN, for example, providing a diskless client solution. A ZFS volume can also serve as an iSCSI disk target. Primarily, interest in supporting the Automated Installer (AI) has been expressed. It is possible to add support without modification of AI manifest processing or modification of the AI server. The changes would be in the AI client (and perhaps in the microroot prior to launching the install service). Administering the iSCSI targets would be a separate task; tools such as the Solaris iscsitadm(1m) would be used. Hardware would include Network Interface Cards and not Host Adapters. Support of both SPARC and x86 can be offered. I would also propose that the iSCSI target be taken from the NIC card which would be manually preconfigured with the target information. A DHCP server can be configured to deliver the iSCSI target information to the NIC, as well. The AI client, running in the microroot environment, would need to be modified to automatically detect the iSCSI target (disk) configured in the NIC, mount it, and include it among potential disk targets for the automated installation. Then the AI client selects a disk target according to the parameters defined in the AI manifest. The MPXIO device name (/dev/dsk/cxtx<long hex string>dx) can be specified in the manifest, providing a reliable identifier that should not change over OpenSolaris releases. Other AI disk selection manifest parameters, such as target disk size or controller type (here, "scsi") could be specified, if the MPXIO device name were not known. A feature not in this proposal for the first release is the integration of the iSCSI target definition into OpenSolaris installer UI. Features ranging from specification of a static IQN (iSCSI qualified name), to an interactive discovery and selection or iSCSI targets might be offered, but perhaps at the cost of considerable design, development, and other resources. A workaround to integrated UI support would be to first load LiveCD, then run iscsiadm(1m) commands from a terminal window to perform target specification, then run the OpenSolaris GUI installer, selecting the iSCSI boot disk, which would then appear as an install target candidate. (The usual procedures to configure the NIC on x86 for iSCSI booting would still be required.) (package SUNWiscsi must be added to LiveCD for this workaround.) It should perhaps be mentioned here that there seems to be no way to completely automatically configure x86 for iSCSI boot without some manual preconfiguration. Setting the BIOS for iSCSI booting as well as enabling DHCP iSCSI initiator discovery appear to be manual procedures. Remote boot firmware may also have to be loaded onto the NIC. Interested parties can find more information at: Getting to know the Solaris iSCSI stack - http://prefetch.net/articles/solarisiscsi.html man pages for iscsiadm, iscsitadm Solaris 10 description for configuring iSCSI boot: http://wikis.sun.com/display/OpenSolarisInfo200906/Configuring+iSCSI+Boot+for+x86+Systems Please review this proposal. Feedback, opinions, corrections, etc. are welcomed. William Schumann
