I may have partially debugged this problem.  (I am now trying ESXi5.5u1 instead of ESXi5.5, but that shouldn't make a big difference).  I ran tcpdump on the machine running cobbler (ie. ops) and rebooted the physical machine on which I want to install esxi.  It looks like the esxi installer is looking for, and really badly wants a file called /boot.cfg file in the root directory of the tftp server.
 
[root@ops ~]# tcpdump -n -i eth0 port 69
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:54:25.689423 IP 172.29.2.0.ah-esp-encap > 172.29.3.31.tftp:  27 RRQ "pxelinux.0" octet tsize 0
13:54:25.729213 IP 172.29.2.0.acp-port > 172.29.3.31.tftp:  32 RRQ "pxelinux.0" octet blksize 1456
13:54:25.799020 IP 172.29.2.0.57089 > 172.29.3.31.tftp:  79 RRQ "pxelinux.cfg/34353739-3232-4d58-5138-333541344245" octet tsize 0 blksize 1408
13:54:25.801884 IP 172.29.2.0.57090 > 172.29.3.31.tftp:  63 RRQ "pxelinux.cfg/01-00-22-64-09-b4-d6" octet tsize 0 blksize 1408
13:54:25.804445 IP 172.29.2.0.57091 > 172.29.3.31.tftp:  67 RRQ "/images/VMware-5.5u1-x86_64/mboot.c32" octet tsize 0 blksize 1408
13:54:28.162020 IP 172.29.2.0.57092 > 172.29.3.31.tftp:  39 RRQ "/boot.cfg" octet tsize 0 blksize 1408

I ran locate to find boot.cfg.  I found 3 copies of boot.cfg and 1 copy of cobbler-boot.cfg

[root@ops ~]# locate boot.cfg
/var/lib/tftpboot/images/VMware-5.5u1-x86_64/boot.cfg
/var/lib/tftpboot/images/VMware-5.5u1-x86_64/cobbler-boot.cfg
/var/www/cobbler/ks_mirror/VMware-5.5u1-x86_64/boot.cfg
/var/www/cobbler/ks_mirror/VMware-5.5u1-x86_64/efi/boot/boot.cfg

All copies of boot.cfg are the same.

[root@ops ~]# diff  /var/lib/tftpboot/images/VMware-5.5u1-x86_64/boot.cfg /var/www/cobbler/ks_mirror/VMware-5.5u1-x86_64/boot.cfg
[root@ops ~]# diff  /var/lib/tftpboot/images/VMware-5.5u1-x86_64/boot.cfg /var/www/cobbler/ks_mirror/VMware-5.5u1-x86_64/efi/boot/boot.cfg  
 
I decided to copy one of these boot.cfg files to the root directory of the tftp server

[root@ops ~]# cp /var/lib/tftpboot/images/VMware-5.5u1-x86_64/boot.cfg /var/lib/tftpboot/

I rebooted the physical machine on which I want to install esxi while running tcpdump on the machine running cobbler (ie. ops).  This time the esxi installation gets a little further.  The tcpdump output is below:

[root@ops ~]# tcpdump -n -i eth0 port 69
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
14:16:50.497304 IP 172.29.2.0.ah-esp-encap > 172.29.3.31.tftp:  27 RRQ "pxelinux.0" octet tsize 0
14:16:50.500842 IP 172.29.2.0.acp-port > 172.29.3.31.tftp:  32 RRQ "pxelinux.0" octet blksize 1456
14:16:50.551803 IP 172.29.2.0.57089 > 172.29.3.31.tftp:  79 RRQ "pxelinux.cfg/34353739-3232-4d58-5138-333541344245" octet tsize 0 blksize 1408
14:16:50.553676 IP 172.29.2.0.57090 > 172.29.3.31.tftp:  63 RRQ "pxelinux.cfg/01-00-22-64-09-b4-d6" octet tsize 0 blksize 1408
14:16:50.556036 IP 172.29.2.0.57091 > 172.29.3.31.tftp:  67 RRQ "/images/VMware-5.5u1-x86_64/mboot.c32" octet tsize 0 blksize 1408
14:16:52.902548 IP 172.29.2.0.57092 > 172.29.3.31.tftp:  39 RRQ "/boot.cfg" octet tsize 0 blksize 1408
14:16:52.905537 IP 172.29.2.0.57093 > 172.29.3.31.tftp:  40 RRQ "/tboot.b00" octet tsize 0 blksize 1408 

On the physical server that I am trying to install esxi, I get the following error:

Loading operating system 
/tboot.b00: file not found 
Fatal error 15 (Not found)

Next I replaced boot.cfg with cobbler-boot.cfg and rebooted my physical machine, watching the tcpdump

[root@ops ~]# cp /var/lib/tftpboot/images/VMware-5.5u1-x86_64/cobbler-boot.cfg /var/lib/tftpboot/boot.cfg 
cp: overwrite `/var/lib/tftpboot/boot.cfg'? y

The tcpdump looks as follows:

[root@ops ~]# tcpdump -n -i eth0 port 69
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
14:28:38.428668 IP 172.29.2.0.ah-esp-encap > 172.29.3.31.tftp:  27 RRQ "pxelinux.0" octet tsize 0
14:28:38.432558 IP 172.29.2.0.acp-port > 172.29.3.31.tftp:  32 RRQ "pxelinux.0" octet blksize 1456
14:28:38.483118 IP 172.29.2.0.57089 > 172.29.3.31.tftp:  79 RRQ "pxelinux.cfg/34353739-3232-4d58-5138-333541344245" octet tsize 0 blksize 1408
14:28:38.485207 IP 172.29.2.0.57090 > 172.29.3.31.tftp:  63 RRQ "pxelinux.cfg/01-00-22-64-09-b4-d6" octet tsize 0 blksize 1408
14:28:38.487562 IP 172.29.2.0.57091 > 172.29.3.31.tftp:  67 RRQ "/images/VMware-5.5u1-x86_64/mboot.c32" octet tsize 0 blksize 1408
14:28:40.834637 IP 172.29.2.0.57092 > 172.29.3.31.tftp:  39 RRQ "/boot.cfg" octet tsize 0 blksize 1408
14:28:40.837974 IP 172.29.2.0.57093 > 172.29.3.31.tftp:  67 RRQ "/images/VMware-5.5u1-x86_64/tboot.b00" octet tsize 0 blksize 1408
14:28:40.840040 IP 172.29.2.0.57094 > 172.29.3.31.tftp:  63 RRQ "/images/VMware-5.5u1-x86_64/b.b00" octet tsize 0 blksize 1408
14:28:40.842016 IP 172.29.2.0.57095 > 172.29.3.31.tftp:  69 RRQ "/images/VMware-5.5u1-x86_64/jumpstrt.gz" octet tsize 0 blksize 1408
14:28:40.844013 IP 172.29.2.0.57096 > 172.29.3.31.tftp:  69 RRQ "/images/VMware-5.5u1-x86_64/useropts.gz" octet tsize 0 blksize 1408
14:28:40.845904 IP 172.29.2.0.57097 > 172.29.3.31.tftp:  63 RRQ "/images/VMware-5.5u1-x86_64/k.b00" octet tsize 0 blksize 1408
14:28:40.847914 IP 172.29.2.0.57098 > 172.29.3.31.tftp:  70 RRQ "/images/VMware-5.5u1-x86_64/chardevs.b00" octet tsize 0 blksize 1408
14:28:40.850042 IP 172.29.2.0.57099 > 172.29.3.31.tftp:  63 RRQ "/images/VMware-5.5u1-x86_64/a.b00" octet tsize 0 blksize 1408
14:28:40.852167 IP 172.29.2.0.57100 > 172.29.3.31.tftp:  66 RRQ "/images/VMware-5.5u1-x86_64/user.b00" octet tsize 0 blksize 1408
14:28:40.854370 IP 172.29.2.0.57101 > 172.29.3.31.tftp:  64 RRQ "/images/VMware-5.5u1-x86_64/sb.v00" octet tsize 0 blksize 1408
14:28:40.856511 IP 172.29.2.0.57102 > 172.29.3.31.tftp:  63 RRQ "/images/VMware-5.5u1-x86_64/s.v00" octet tsize 0 blksize 1408
14:28:40.858534 IP 172.29.2.0.57103 > 172.29.3.31.tftp:  70 RRQ "/images/VMware-5.5u1-x86_64/ata_pata.v00" octet tsize 0 blksize 1408
 
... ...
 

The console of the physical esxi machine shows the machine successfully booting esxi5.5u1.

My conclusion is that copying cobbler-boot.cfg to /var/lib/tftpboot/boot.cfg resolved the problem.  Would any cobbler developers or experts please verify that this is the correct thing to do?

Now onto kickstarting ESXi5.5u1 ...

I hope this post is helpful to others trying to gPXE boot and kickstart ESXi5* installs.
-Razi


On Sat, Apr 26, 2014 at 10:24 PM, Razi Khaja <razi.khaja@gmail.com> wrote:

I'm running Centos 6.5 and Cobbler 2.7.0 checked out from github:

[root@ops ~]# cat /etc/redhat-release

CentOS release 6.5 (Final)

[root@ops ~]# cobbler version

Cobbler 2.7.0

  source: c5a7bb2, Sun Apr 27 00:24:56 2014 +0200

  build time: Sat Apr 26 19:28:28 2014

My cobbler installation is able to successfully pxe boot systems on which I install CentoOS 6.5, so I know that it is working, but I am having difficulty with gpxe booting esxi5.5.

I have successfully imported the ESXi5.5 iso: VMware-VMvisor-Installer-5.5.0-1331820.x86_64.iso

I have installed the packages for gpxe, however, when I boot the machine on which I want to install ESXi5.5, I get the following error: 

Loading operating system
Configuration error while parsing /boot.cfg
Fatal error: 15 (Not found)  

Below is the distro report:

[root@ops ~]# cobbler distro report --name=vmware-5.5-x86_64
Name                           : vmware-5.5-x86_64
Architecture                   : x86_64
TFTP Boot Files                : {'$local_img_path/*.*': '/var/www/cobbler/ks_mirror/vmware-5.5-x86_64/*.*'}
Breed                          : vmware
Comment                        : 
Fetchable Files                : {}
Initrd                         : /var/www/cobbler/ks_mirror/vmware-5.5-x86_64/imgpayld.tgz
Kernel                         : /var/www/cobbler/ks_mirror/vmware-5.5-x86_64/mboot.c32
Kernel Options                 : {}
Kernel Options (Post Install)  : {}
Kickstart Metadata             : {'tree': 'http://@@http_server@@/cblr/links/vmware-5.5-x86_64'}
Management Classes             : []
OS Version                     : esxi55
Owners                         : ['admin']
Red Hat Management Key         : <<inherit>>
Red Hat Management Server      : <<inherit>>
Template Files                 : {'/etc/cobbler/pxe/bootcfg_esxi55.template': '$local_img_path/cobbler-boot.cfg'}

I have already read previous similar posts for previous versions of esxi5, but did not find those helpful:

https://lists.fedorahosted.org/pipermail/cobbler/2014-February/009284.html

https://lists.fedorahosted.org/pipermail/cobbler/2013-June/008869.html

Any help would be greatly appreciated,

-Razi