[syslinux] Fwd: EFI & PXE-booting: very slow TFTP performance on a VMWare test setup

[Oscar Roozen]

[re-sent to list]

On Thu, Jun 18, 2015 at 7:18 PM, Gene Cumm <gene.cumm at gmail.com> wrote:
> I see the nice exponential-like decay of IO rate :(

Did you see this only on vmware or also in other environments?


On Sat, Jun 20, 2015 at 1:44 PM, Gene Cumm <gene.cumm at gmail.com> wrote:
> Boot loader environments rarely benefit from a second CPU.  The best
> way to not miss an interrupt in a VM boot environment is to not
> overcommit.

I'm still a bit worried about the 100% CPU load while waiting for UDP
packets to arrive..
Wouldn't it be better to just 'hlt' somehow and have the interrupts
wake the CPU up?

> Consider one of the following workarounds:
>
> 1) HTTP/FTP.  Loading individual files over HTTP/FTP would be
> suggested for a large file anyways.  For your situation, I'd suggest
> trying to use DHCP option 210, either embedded in option 43 or
> hard-coded into syslinux.efi as an after-DHCP option with
> pxelinux-options.  Setting the plain option would require forcing your
> dhcpd to always insert it (isc-dhcpd after v3 I think can do this) as
> no PXE client will ever request it.  I have http://myip/tftp/ pointing
> at my tftpd root just for this purpose.

I went the HTTP-way for now:

if option architecture-type = 00:09 {
    filename "efi64/syslinux.efi";
    option pxelinux.pathprefix  "http://myserverip/tftp/efi64/";
} elsif option architecture-type = 00:07 {
    # efi32 not supported.
} else {
    filename "bios/pxelinux.0";
}

Thanks!

--

Oscar Roozen
Linux Developer




oscar.roozen at brightcomputing.com

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