Running a UDP Remote Console with Linux 2.6

Bruce Perens writes "Many system admins have learned how to use syslog to log events of remote systems. But when the kernel crashes, its final messages never get to syslog. If you don't have a remote console manager, you won't see them, unless you run netconsole."

Comments

Same thing as sending syslog to remote loghost?

[menscher]

I really don't see much benefit here. Seems like someone just took syslogd and made it a kernel module. Just one more piece of the kernel to crash. Personally I'd rather keep the kernel as small as possible. Less to go wrong that way.

While on the topic, though, it would be nice if Linux did something similar to IRIX, where a crash would save the kernel coredump to the swap partition. Yes, I know the Linux Kernel Crash Dump project does this, but they're not exactly stable yet (hell, their website won't even load right now).

Re:Same thing as sending syslog to remote loghost?

[drdink]

This is a useful tool for those of us who have a slew of machines on a single network segment and don't want to have an expensive KVM or 47 monitors. The ability to put your consoles over the same wire you put your normal network traffic over is great. It is like those cable companies that also provide phone service over your cable line, sort of...
IRIX isn't the only operating system that does crashdumps. I've found them to be an invaluable tool for debugging FreeBSD. It has supported them for quite a long time. The ability to gdb your kernel and the vm after you reboot and see exactly where things went wrong is great. I still don't understand why Linux lacks this.

SNMP trap?

[professorfalcon]

Why not just send an SNMP trap?

Re:some conditions..

[emag]

3. Ok, seemingly hard lockups are out - but these are more and more uncommon with 2.6 - but nearly everything else is dumpable, unless it screws with the NIC driver itself?

Well, a friend of mine using 2.6 is experiencing random lockups (we suspect either hardware problems, or ghosts), with nothing ever logged. However, he can still ping the machine even after it's locked up, but the console also doesn't respond. I've pointed him at this article, and he's going to try enabling netconsole to see if anything from the kernel is getting lost. Hopefully it'll help figure out what the problem is.