[Beowulf] SATA II - PXE+NFS - diskless compute nodes

[Joe Landman]

Hi Simon

Simon Kelley wrote:
> Joe Landman wrote:
>>>> I would hazard that any DHCP/PXE type install server would struggle
>>>> with 2000 requests (yes- you arrange the power switching and/or
>>>> reboots to stagger at N second intervals).
> 
>> fwiw:  we use dnsmasq to serve dhcp and handle pxe booting.  It does a
>> marvelous job of both, and is far easier to configure (e.g. it is less
>> fussy) than dhcpd.
> 
> Joe, you might like to know that the next release of dnsmasq includes a
> TFTP server so that it can do the whole job. The process model for the
> TFTP implementation should be well suited to booting many nodes at once
> because it multiplexes all the connections on the same process. My guess
>  is that will work better then having inetd fork 2000 copies of tftpd,
> which is what would happen with traditional TFTP servers.

I am glad to hear this.  I haven't found a case that ISC DHCP does a 
better job than dnsmasq for our clusters:  the former is hard to 
configure properly; it is quite fussy.  Add in that we don't need to 
configure bind on the cluster (really doesn't make much sense in most 
cases, unless you are doing some sort of fail-over cluster config) when 
we use dnsmasq... this is a good tool.

We haven't explicitly enabled it in our Rocks roll as a default option, 
but we typically turn off bind and the local dhcp server there as this 
does a much better job.  For our non-rocks units, we simply use this by 
default.

Great job Simon!

Joe

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Joseph Landman, Ph.D
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