[syslinux] pxechain.com and gpxelinux.0 odd behavior

Hans Lellelid hans at velum.net
Thu Aug 8 10:05:00 PDT 2013

I've spent a lot more time with this today, trying to get this working with
4.07, 5.01, and 5.10 ... no luck, but I did have a few follow-up questions.

(1) Should it be possible to use the newer (e.g. 5.10) version of syslinux
and use http:// URLs for both the initial vmlinuz image and also the
initrd? -- As I was doing before with gpxelinux.0?  A naive attempt to use
lpxelinux.0 on our cobbler box w/o any chainloading is failing like this:

Loading http://<cobbler-ip>/cobbler/images/CentOS-5.9-i386/vmlinuz ...
netconn_write error -5
Boot failed: press a key to retry, or wait for reset...

Earlier attempts to chain load from lpxelinux.0 ->
tftp://server2/lpxelinux.0  also failed, I suspect for a similar error.

(2) The new gpxelinux.0 in 5.10 seems to not work at all (with our VMWare
VMs, anyway).  That may be on the known-bugs list.

(3) I assume I should be using pxechn.c32 instead of pxechain.com now

I updated the pxelinux.cfg/default on my first-stop server to look like

label cobbler
COM32 pxechn.c32
append tftp://

This specific example (using lpxelinux.0) refuses to load the http-url
kernel from my cobbler box, but if I use non-URL paths (i.e. TFTP) for
kernel and initrd it works just fine.

Any further help appreciated! :)

All I need to do here is have support for multiple pxe servers (chain) and
support loading kernel and initrd over http since tftp is unusably slow for
these larger files in certain networks.  I'm happy to try whatever versions
or combinations of pxelinux.0/lpxelinux.0/gpxelinux.0/etc. get me there :)


On Thu, Aug 8, 2013 at 9:46 AM, Hans Lellelid <hans at velum.net> wrote:

> On Wed, Aug 7, 2013 at 7:26 PM, Gene Cumm <gene.cumm at gmail.com> wrote:
>> <snip>
>> After my experiences with writing/testing pxechn.c32, I'm not
>> surprised that this happens.  What version(s) have you used?
>> One of the goals of lpxelinux.0 is to replace gpxelinux.0 for HTTP/FTP
>> fetch capability.  This is available in versions 5.10+ and 6.00+ (BIOS
>> only in 6.00+) however it still needs more testing/debugging as there
>> are a few known issues (listed in bugzilla.syslinux.org ).
> I first tried this setup with version 4.02 (then with a pxehain.com from
> 4.04 [?] pulled in to get around known bug, which probably was a dumb idea)
> and then more recently with syslinux 4.06  on both systems.  I'll happily
> try newer versions if they might work -- and give lpxelinux.0 a shot if
> that'll work w/ my (vmware) systems too.
> Hans

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