| |
| started by Ingo Molnar <mingo@redhat.com>, 2001.09.17 |
| 2.6 port and netpoll api by Matt Mackall <mpm@selenic.com>, Sep 9 2003 |
| |
| Please send bug reports to Matt Mackall <mpm@selenic.com> |
| |
| This module logs kernel printk messages over UDP allowing debugging of |
| problem where disk logging fails and serial consoles are impractical. |
| |
| It can be used either built-in or as a module. As a built-in, |
| netconsole initializes immediately after NIC cards and will bring up |
| the specified interface as soon as possible. While this doesn't allow |
| capture of early kernel panics, it does capture most of the boot |
| process. |
| |
| It takes a string configuration parameter "netconsole" in the |
| following format: |
| |
| netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr] |
| |
| where |
| src-port source for UDP packets (defaults to 6665) |
| src-ip source IP to use (interface address) |
| dev network interface (eth0) |
| tgt-port port for logging agent (6666) |
| tgt-ip IP address for logging agent |
| tgt-macaddr ethernet MAC address for logging agent (broadcast) |
| |
| Examples: |
| |
| linux netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc |
| |
| or |
| |
| insmod netconsole netconsole=@/,@10.0.0.2/ |
| |
| Built-in netconsole starts immediately after the TCP stack is |
| initialized and attempts to bring up the supplied dev at the supplied |
| address. |
| |
| The remote host can run either 'netcat -u -l -p <port>' or syslogd. |
| |
| WARNING: the default target ethernet setting uses the broadcast |
| ethernet address to send packets, which can cause increased load on |
| other systems on the same ethernet segment. |
| |
| NOTE: the network device (eth1 in the above case) can run any kind |
| of other network traffic, netconsole is not intrusive. Netconsole |
| might cause slight delays in other traffic if the volume of kernel |
| messages is high, but should have no other impact. |
| |
| Netconsole was designed to be as instantaneous as possible, to |
| enable the logging of even the most critical kernel bugs. It works |
| from IRQ contexts as well, and does not enable interrupts while |
| sending packets. Due to these unique needs, configuration can not |
| be more automatic, and some fundamental limitations will remain: |
| only IP networks, UDP packets and ethernet devices are supported. |