This error indicates that your iSCSI root path syntax is incorrect.  The syntax of an iSCSI root path is defined by [[http://tools.ietf.org/html/rfc4173|RFC 4173]] to be

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

Here are some examples of valid iSCSI root paths:

    iscsi:iscsi.example.com::::iqn.1991-05.com.microsoft:snubfin-msdos622-target
    
    iscsi:192.168.0.1:::1:iqn.2000-04.uk.co.fensystems:iscsi-boot
    
    iscsi:10.0.0.5:::1-7:iqn.2010-11.private:winsrvr2008

Note that the ''<protocol>'', ''<port>'', and ''<LUN>'' fields are allowed to be empty, and that the ''<targetname>'' field may (and often will) contain a colon.