[mythtv-users] SOLVED: Questions on PXE booting a frontend

[Marc Tousignant]

Thanks to everyone who helped me on this.  I now have both Zotac IONITX
machines doing PXE boots from the master backend, with no attached storage
whatsoever.  They are running MythDora 10.21 which is based on FC10.  Here
is a summary for the record.

1. No kernel or kernel module recompilation was needed.

2. A lot of people reported success with two DHCP servers on the same
network, as long as care is taken to avoid conflicts.  I set up a DHCP
server on the master backend to assign static IPs to the two frontends, with
PXE enabled, and nothing else.  So far, so good.

3. I'm too busy basking in the success of PXE booting and NFS root mounting
to do torture testing on NFS fault tolerance...

4. The mkinitrd man page is 5 years out of date.  The correct grub kernel
line for NFS-mounting root (without involving PXE) in my example above is
simply:
    kernel /vmlinuz-2.6.27.9-159.fc10.i686 ro
root=192.168.0.205:/storage1/frontends/mythfe2/ROOT
Also be sure to run mkinitrd against an /etc/fstab that lists an NFS root
file system type.

Other tips:

o Disable the NetworkManager service, otherwise the system will probably
hang during bootup.

o My files in the pxelinux.cfg directory look like this:
    DEFAULT linux
    LABEL linux
    KERNEL vmlinuz-2.6.27.9-159.fc10.i686
    APPEND ro root=192.168.0.205:/storage1/frontends/mythfe2/ROOT
initrd=initrd-nfs-2.6.27.9-159.fc10.i686.img
Notice the addition of initrd=... to the kernel arguments.  I have a
separate file for each frontend because each NFS root path is different.

o I noticed that mkinitrd and the associated nash program support a "dhcp"
root file system type, which seems basically the same as "nfs" except that
the root-path is taken from the DHCP server's response.  It would probably
be better to add the root paths to /etc/dhcpd.conf, and then only have a
single "default" file in the pxelinux.cfg directory.

o The frontend now idles at 18 watts according to the Kill-a-Watt device. 
I'm thinking of replacing the 2 1GB SDRAM modules with a single 2GB module,
which would leave more open space for passive cooling, and perhaps even drop
the power usage by a watt...

Jim

---------------

Jim,

I am using PXElinux with a Gentoo based system. I originally tried to get
PXEGrub to work but it failed for me. Instead of tracking down the issue I
switched to a method that I knew worked from others experience.

If you ever figure out how to get suspend to work with wake on USB, post to
the list.
I got suspend working, but as soon as I enable the USB ports, the machine
wakes automatically.
If I disable them again the machine stays in suspend but I have to hit the
power button to resume.

Enabling USB selective suspend/resume and wakeup in the kernel makes things
worse. The machine will only suspend to ram once per boot, even with USB
wakeup off.
I'm using a custom built 2.6.30, if the prebuilt 2.7.27 you have works with
wake on usb, I would like to get a copy of the kernel config to try and find
out why.

Marc