From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: Make ipconfig.c work as a loadable module. Date: 07 Mar 2003 19:03:24 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Russell King , Chris Dukes , Alan Cox , Jeff Garzik , Robin Holt , Linux Kernel Mailing List , Return-path: To: Bogdan Costescu In-Reply-To: Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Bogdan Costescu writes: > On Fri, 7 Mar 2003, Russell King wrote: > > > Which version is overly bloated? > > Which version is huge? > > Which version is compact? > > ... and the size is not important only because we want to make everything > smaller, but because of how it's commonly used (at least in the clustering > world from which I come): > > the mainboard BIOS or NIC PROC contains PXE/DHCP client; data is > transferred through UDP, with very poor (if any) congestion control. Only because the implementations suck. See etherboot. > Congestion control means here both extreme situations: if packets don't > arrive to the client, it might not ask again, ask only a limited number of > times or give up after some timeout; if the server has some faster NIC to > be able to handle more such requests, it might also send too fast for a > single client which might drop packets. In some cases, if such situation > occurs, the client just blocks there printing an error message on the > console, without trying to restart the whole process and the only way to > make it do something is to press the Reset button or plug in a keyboard... > When you have tens or hundreds of such nodes, it's not a pleasure ! But this is all before the kernel is loaded. Having booted a 1000 node cluster with TFTP and DHCP. From a single host with even being in the same town, I think I have some room to talk. > Booting a bunch of such nodes would become problematic if they need > to transfer more data (=initrd) to start the kernel and so network booting > would become less reliable. Please note that I'm not saying "ipconfig has > to stay" - just that any solution should not dramatically increase the > size of data transferred before the jump to kernel code. Right. But I would suggest fixing your NBP (what PXE load) which must be < 64K anyway if you have noticeable reliability problems. Not that I even suggest using PXE for production use anyway. But sometimes you are stuck with what you can do. Eric