Web extra: iSCSI: Beyond Windows

The vast majority of Internet SCSI (iSCSI) deployments involve servers running Microsoft Windows software, but other platforms support the technology, too.

Industry executives estimated that 85 percent to 90 percent of iSCSI storage-area network deployments occur in Windows environments. The reason: Microsoft’s early development of an iSCSI initiator, the software that allows a server to participate in an iSCSI data exchange with storage devices.

“Microsoft has put such a thrust around iSCSI initiators,” said Bill Chambers, co-founder and chief executive officer at LeftHand Networks.

Other operating systems haven’t been as quick to support iSCSI, however.

Dave Dale, industry evangelist at Network Appliance, said Linux has been slower than Microsoft to include iSCSI initiators and input/output multipath drivers in the operating system. A multipath driver ensures that if a connection fails, the host operating system’s commands to storage get through on an alternate path, he said.

Dale added that he expects to see more Linux iSCSI deployments, particularly once multipathing for Linux becomes available in the next six months.

Currently, iSCSI initiators are built into Red Hat Enterprise Linux and Novell’s SUSE Linux Enterprise Server 9. The next version of SUSE Linux Enterprise Server, due later this year, will include an iSCSI initiator and targets, software that will allow storage devices to handle iSCSI traffic, according to a Novell spokesman.

In the Unix world, iSCSI initiators have been built into operating systems such as IBM’s AIX, Sun Microsystems’ Solaris and Hewlett-Packard’s HP-UX, Dale said.

In addition, Novell’s NetWare 6.5 includes an iSCSI initiator and target. An iSCSI initiator is available via download for NetWare 6.0 and NetWare 5.1.