OK... so I have resolved the problem. This was a network issue:
My network config looked like this:
# Generated settings:
IFNAME[0]="br0"
BONDNAME[0]="bond0"
BONDING_MIIMON[0]="100"
BRNAME[0]="br0"
BRSTP[0]="no"
BRFD[0]="0"
BONDING_MODE[0]="1"
BONDNICS[0]="eth0"
BRNICS[0]="bond0"
PROTOCOL[0]="ipv4"
USE_DHCP[0]="no"
IPADDR[0]="10.0.0.10"
NETMASK[0]="255.255.254.0"
GATEWAY[0]="10.0.0.1"
DNS_SERVER1="10.0.0.1"
USE_DHCP6[0]="yes"
DHCP6_KEEPRESOLV="no"
VLANS[0]="1"
SYSNICS="1"
VLANS[0]="1,103"
The output from my original post contains the clue:
bond0: (slave eth0): Enslaving as a backup interface with a down link
I simply edited my config to as simple as possible:
# Generated settings:
# Default settings:
IFNAME[0]="eth0"
PROTOCOL[0]="ipv4"
USE_DHCP[0]="yes"
And my host came up after booting with this.
Obviously this is not a generic solution to this problem. Simply put `udev` was failing to bring up the interface. In order to debug this you need to boot the server into single user mode by adding `single` to the kernel's boot paramters.
Or you can edit `syslinux.cfg-` as follows:
default menu.c32
menu title Lime Technology, Inc.
prompt 0
timeout 50
label Unraid OS
menu default
kernel /bzimage
append initrd=/bzroot
label Unraid OS GUI Mode
kernel /bzimage
append initrd=/bzroot,/bzroot-gui
label Unraid OS Safe Mode (no plugins, no GUI)
kernel /bzimage
append initrd=/bzroot unraidsafemode
label Unraid OS GUI Safe Mode (no plugins)
kernel /bzimage
append initrd=/bzroot,/bzroot-gui unraidsafemode
label Memtest86+
kernel /memtest
label Single User Mode
kernel /bzimage
append initrd=/bzroot single
Once in single user mode you can debug the issue. I established that simply brining up the interface manually by doing:
/sbin/ip link set eth0 up
/sbin/ip addr add 10.0.0.10/24 dev eth0 # edit this for your network obviously
/sbin/ip route add default via 10.0.0.1
Given that I know the interface was working I followed the steps to manually bring up the bond0, and it failed so I knew the config was gronked. I reverted to the simple dhcp config and that resolved my problem.
I hope this helps other users.