First thing, credit where due:
Cisco.com iSCSI Configuration Guide (Please read first!)
Peter Revill has some great posts on iSCSI (Thanks, Peter!)
Ben King has a good post on setting up iSCSI interfaces for ESXi in UCS (Thanks, Ben!)
For those looking for a quick reference, template is at the bottom of this post.
What is iSCSI?
iSCSI (Internet Small Computer Systems Interface) is a SCSI transport mechanism over IP. You take the SCSI payload (Reads/Writes), encapsulate it in TCP and send it over IP. This is a completely separate stack than FC, and does not rely on FC at all. You can, however, compare it to the same way that FCIP transports SCSI over IP. The differences can be seen in the packet:
| SCSI | FC | FCIP | TCP | IP | Eth |
| SCSI | iSCSI | TCP | IP | Eth |
iSCSI works like any storage protocol, you have initiators and targets. When comparing to Fibre Channel, note these differences: (more…)