====== SAN URIs ======

When booting from SAN, you can specify the location of the SAN target using a SAN URI.  For example, when using the ''[[:cmd:sanboot]]'' command in an iPXE script:

    #!ipxe
    sanboot iscsi:10.253.235.1::::iqn.2010-04.org.ipxe:rabbit

or as the ''[[:cfg:root-path]]'' DHCP option (using [[:howto:dhcpd|ISC dhcpd]]):

    option root-path "iscsi:10.253.253.1::::iqn.2010-04.org.ipxe:rabbit";

or as the ''[[:cfg:root-path]]'' DHCP option (using the [[:howto:msdhcp|Microsoft DHCP server]]):

{{ :screenshots:msdhcp_set_root_path.png?207x231 |Root path in the Microsoft DHCP server}}

The format of the SAN URI depends upon the SAN protocol that you are using.

===== iSCSI =====

The format of an iSCSI SAN URI is defined by [[http://tools.ietf.org/html/rfc4173|RFC 4173]].  The general syntax is:

    iscsi:<servername>:<protocol>:<port>:<LUN>:<targetname>

For example:

    iscsi:10.253.235.1::::iqn.2010-04.org.ipxe:rabbit
    iscsi:boot.ipxe.org::::iqn.2010-04.org.ipxe.boot:public
    iscsi:192.168.0.1:::1:iqn.1991-05.com.microsoft:msdos622-target
    iscsi:opensolaris.home::::iqn.1986-03.com.sun:02:e9abf4cd-714b-c6ec-d017-eea5a56252ed

  * ''<servername>'' is the DNS name or IP address of the iSCSI target.
  * ''<protocol>'' is ignored and can be left empty.((The only valid value for ''<protocol>'' is ''6'', indicating that the protocol is TCP.))
  * ''<port>'' is the TCP port of the iSCSI target.  It can be left empty, in which case the default port (3260) will be used.
  * ''<LUN>'' is the SCSI LUN of the boot disk, in hexadecimal.  It can be left empty, in which case the default LUN (0) will be used.
  * ''<targetname>'' is the iSCSI target IQN.

If you are using iSCSI authentication, then you will need to configure the ''[[:cfg:username]]'' and ''[[:cfg:password]]'' settings (and possibly also the ''[[:cfg:reverse-username]]'' and ''[[:cfg:reverse-password]]'' settings) before attempting to connect to the SAN target.  There is no way to specify usernames and passwords directly within the iSCSI SAN URI.

{{ :clipart:disk.jpeg?240x186|A disk}}

===== AoE =====

The format of an AoE SAN URI is:

    aoe:e<n>.<m>

For example:

    aoe:e0.0
    aoe:e0.1
    aoe:e2.4

  * ''<n>'' is the AoE major device number (also known as the shelf number).
  * ''<m>'' is the AoE minor device number (also known as the slot number).

There is no way to specify a particular network device within the AoE SAN URI.  iPXE will use the most recently opened network device.

===== HTTP =====

The format of an HTTP SAN URI is simply a standard HTTP URI.  For example:

    http://boot.ipxe.org/freedos/fdfullcd.iso

Note that the HTTP server must support range requests, otherwise SAN booting will fail.

===== FCP (including FCoE) =====

The format of an FCP SAN URI is:

    fcp:<wwn>:<lun>

For example:

    fcp:20:00:00:1f:16:bc:fe:2f:0
    fcp:20:00:52:54:00:9a:ba:bc:0

  * ''<wwn>'' is the Fibre Channel Port WWN of the FCP target.
  * ''<lun>'' is the SCSI LUN of the boot disk.

There is no separate syntax for FCoE, and there is no way to specify a particular network device within an FCP/FCoE SAN URI.  FCoE interfaces are created automatically whenever an FCoE fabric is detected, and iPXE will search for the FCP target on all open FCoE interfaces.