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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/networking/netconsole.txt |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/networking/netconsole.txt')
-rw-r--r-- | Documentation/networking/netconsole.txt | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/Documentation/networking/netconsole.txt b/Documentation/networking/netconsole.txt new file mode 100644 index 000000000000..53618fb1a717 --- /dev/null +++ b/Documentation/networking/netconsole.txt | |||
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1 | |||
2 | started by Ingo Molnar <mingo@redhat.com>, 2001.09.17 | ||
3 | 2.6 port and netpoll api by Matt Mackall <mpm@selenic.com>, Sep 9 2003 | ||
4 | |||
5 | Please send bug reports to Matt Mackall <mpm@selenic.com> | ||
6 | |||
7 | This module logs kernel printk messages over UDP allowing debugging of | ||
8 | problem where disk logging fails and serial consoles are impractical. | ||
9 | |||
10 | It can be used either built-in or as a module. As a built-in, | ||
11 | netconsole initializes immediately after NIC cards and will bring up | ||
12 | the specified interface as soon as possible. While this doesn't allow | ||
13 | capture of early kernel panics, it does capture most of the boot | ||
14 | process. | ||
15 | |||
16 | It takes a string configuration parameter "netconsole" in the | ||
17 | following format: | ||
18 | |||
19 | netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr] | ||
20 | |||
21 | where | ||
22 | src-port source for UDP packets (defaults to 6665) | ||
23 | src-ip source IP to use (interface address) | ||
24 | dev network interface (eth0) | ||
25 | tgt-port port for logging agent (6666) | ||
26 | tgt-ip IP address for logging agent | ||
27 | tgt-macaddr ethernet MAC address for logging agent (broadcast) | ||
28 | |||
29 | Examples: | ||
30 | |||
31 | linux netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc | ||
32 | |||
33 | or | ||
34 | |||
35 | insmod netconsole netconsole=@/,@10.0.0.2/ | ||
36 | |||
37 | Built-in netconsole starts immediately after the TCP stack is | ||
38 | initialized and attempts to bring up the supplied dev at the supplied | ||
39 | address. | ||
40 | |||
41 | The remote host can run either 'netcat -u -l -p <port>' or syslogd. | ||
42 | |||
43 | WARNING: the default target ethernet setting uses the broadcast | ||
44 | ethernet address to send packets, which can cause increased load on | ||
45 | other systems on the same ethernet segment. | ||
46 | |||
47 | NOTE: the network device (eth1 in the above case) can run any kind | ||
48 | of other network traffic, netconsole is not intrusive. Netconsole | ||
49 | might cause slight delays in other traffic if the volume of kernel | ||
50 | messages is high, but should have no other impact. | ||
51 | |||
52 | Netconsole was designed to be as instantaneous as possible, to | ||
53 | enable the logging of even the most critical kernel bugs. It works | ||
54 | from IRQ contexts as well, and does not enable interrupts while | ||
55 | sending packets. Due to these unique needs, configuration can not | ||
56 | be more automatic, and some fundamental limitations will remain: | ||
57 | only IP networks, UDP packets and ethernet devices are supported. | ||