On 03/14/2010 06:08 PM, Dieter Plaetinck wrote:
On Sun, 14 Mar 2010 06:39:20 -0300 Gerardo Exequiel Pozzi<vmlinuz386@yahoo.com.ar> wrote:
Hello
I recently done some changes for archiso, to make it booteable via PXE (Preboot eXecution Environment) and using NBD (Network Block Device). Also a minimal server script can be launched to act as server ;)
cool.
absolutelly :)
i always wanted support for pxe. is there a specific reason to choose nbd over nfs?
Good question. I chosed NBD instead of NFS because is really simple. 1) [From client side] No changes needed to [archiso] hook. Just add another hook [nbd]. This hook setup a /dev/archiso pointing to /dev/nbd0 (created via only one command) I think that doing via NFS requires: - nfs hook can not be used directly (archiso mount handler will be over nfs mount handler) - mounting nfs must be under /bootmnt, and in archiso hook must skip mouting /dev/archiso if booted from nfs. 2) [From server side] Run only one command to setup the NBD server. I think that doing via NFS requires: - setup exports, and other files. - launch nfs and all daemon required (rpcbind, nfs-common, nfs-server)
If booted from network, there is a [nbd] hook, (based on [net]), that configures an IP address, then setup a /dev/nbd0 (via nbd-client). (and /dev/archiso will point to this device), all the rest is done by current archiso hook :) (copytoram option can be used) If booted normally, [nbd] hook does nothing. Inside the /root, there is a simple script that launches dnsmasq enabling tftp and dhcp server, finally start the nbd-server that serve the iso file via network.
i'm confused, this whole thing is meant for clients, right? what does the tftp/dhcp server has to do with the client?
In other words: - archiso with [nbd] hook, is capable to boot completelly from ethernet. - The [nbd] hook detects that if ip= parameter is present, the execute the needed actions, if no ip= paramter does nothing. - The ip= parameter is automagically added via IPAPPEND 1 at syslinux config (retrived from server) Thats all for archiso. OK but there is a "bonus", in my custom config (avr-toolchain). I added two aditional files (pxelinux.0 pxelinux.cfg/default) and two packages (dnsmasq nbd) to make this live-media capable to acts as server for archiso. The "bonus^2" in my live-media there is one dirty script thats execute dnsmasq and nbd-server.
also, do you think we could just merge this in archiso and always use the nbd hook? (knowing that it won't do anything in 99% of the cases, when people do a regular boot)
Maybe: - initramfs image grows from 5M to 8M. - nbd hooks does nothing in normal process (there is no ip= parameter) An aditional work can be done if integrated in archiso: - if copytoram option is used, there is no need to keep nbd-client connected to the server. Aditional check can be added to disconnect from the server. So the live-media will be completelly independent. Anyway this conection is not used at all, but to do the right things ;) Videos :P http://www.youtube.com/watch?v=aoeC2ZpGQFQ (booting normal from USB) http://www.youtube.com/watch?v=inJNXsTQBOA (booting from PXE) Comments welcomed. Good week ;) -- Gerardo Exequiel Pozzi ( djgera ) http://www.djgera.com.ar KeyID: 0x1B8C330D Key fingerprint = 0CAA D5D4 CD85 4434 A219 76ED 39AB 221B 1B8C 330D