On Mon, 2009-02-23 at 15:07 -0500, Warren Togami wrote: > Hi Victor, > > I didn't test this patch yet, but I need this kind of structure in order > to implement different kinds of netboot. I fugured it would be needed, and I certainly don't want to bloat up the main init script with code that will not be needed on most systems. :) > root=dhcp is a kernel cmdline given by the bootloader (syslinux, grub, > pxelinux, etc.) which directs the initrd during runtime to bring up eth0 > and do DHCP. It then mounts the rootfs depending on options given by > the DHCP server. Fedora 10 mkinitrd implements the following two types > of mounts with root=dhcp. > > option root-path "172.31.100.254:/path/to/target_root"; > option root-path "nbd:172.31.100.254:2000:squashfs:ro"; Interesting -- I have been working on implementing code to detect and configure network interfaces according to the netboot.txt kernel document. The code I have written so far is browseable at http://git.fnordovax.org/dracut/log/?h=network-configurability (and it even works some of the time), and I would appreciate input from someone who actually uses that functionality on a daily basis. > An existing RFC specifies syntax for iscsi that could be implemented as > well. (Although iscsi is problematic because some types require > authentication.) Yeah, I was thinking of what sort of structure would be needed to let someone else write code to handle multipath iscsi over teamed nics without having to patch the main init script. > Arbitrary types of root=dhcp rootfs mounts can be > implemented with hooks made possible with your patch. > > Generation > ========== > ∘ read mode from dracut.conf i.e. MODE=network > ∘ if network > ‣ install network modules > ‣ install tools (mount.nfs, nbd, etc.) > ‣ install squashfs.ko > ‣ install custom udev rules to handle network Not a problem -- I have not gotten to the nfs stuff yet, but the above branch already works well enough let udev bring network interfaces up according to what is passed on the kernel command line (assuming I did not break it again, and assuming you are using dhcp or statically configuring your interfaces -- I have no plans for adding bootp or rarp support, but patches to do so are happily accepted). > Boot (contents of udev rule) > ============================ > ∘ if root=dhcp (or later hard coded network) > ‣ ifup eth0 > ‣ dhclient The above branch already knows how to do this stuff. > ‣ parse root-path Probably cannot do this in udev, but easily doable from a mount hook. > ‣ if nbd > • modprobe nbd > • nbd-client with parameters > • (mount rootfs) > ‣ if nfs > • (mount rootfs) I was planning to handle nfsroot in a mount hook as well, extending it to handle nbd should not be a problem. > Warren Togami > wtogami@xxxxxxxxxx > -- > To unsubscribe from this list: send the line "unsubscribe initramfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Victor Lowther RHCE# 805008539634727 LPIC-2# LPI000140019 -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
