Hi David, On Tue, Jan 26, 2010 at 10:46:40AM -0800, David Mathog wrote: > > David Mathog wrote: > > Will a logger > > message for "kern" test it, or is there some other way to force a > > printk? I'm afraid the logger method might look like it is working, but > > just go through the usual syslog channels instead of netconsole. > > Too optimistic. With netconsole (supposedly) running on the local node Correct. > > logger -p kern.err "test from me" > > only shows up in the log file on that node. No chance of confusion ;-). > There is no explicit network logging of kern.err in /etc/syslog.conf, > since I figured syslog is never going to be able to actually log > anything after a kernel error. > > dmesg shows that netconsole started and thinks it is working: > > netconsole: local port 6666 > netconsole: local IP 192.168.1.20 > netconsole: interface eth0 > netconsole: remote port 514 > netconsole: remote IP 192.168.1.220 > netconsole: remote ethernet address 00:30:48:59:f8:ff > console [netcon0] enabled > netconsole: network logging started > > However, absolutely nothing comes over netconsole when a node reboots. > > Searched a lot and finally found out how to test netconsole: > > [r...@monkey20 rc6.d]# echo 'p' > /proc/sysrq-trigger > [r...@monkey20 rc6.d]# echo 't' > /proc/sysrq-trigger > [r...@monkey20 rc6.d]# echo 'm' > /proc/sysrq-trigger > > and it generated these on the syslogd machine > > Jan 26 10:21:12 monkey20.cluster SysRq : > Jan 26 10:21:12 monkey20.cluster Show Regs > Jan 26 10:21:35 monkey20.cluster SysRq : > Jan 26 10:21:35 monkey20.cluster Show State > Jan 26 10:21:52 monkey20.cluster SysRq : > Jan 26 10:21:52 monkey20.cluster Show Memory > > Notice the contentless messages, which were the same as on the video > console. This is a log level issue, change it with dmesg or > > [r...@monkey20 rc6.d]# echo '9' > /proc/sysrq-trigger > [r...@monkey20 rc6.d]# echo 'm' > /proc/sysrq-trigger > > and then a pile of memory information shows up on both the syslog side > and the video console. > > The default log level on these machines is 3. If the kernel panics with > it set to that, will the messages that result be "contentless", like the > ones above?
Hmmm, we had no kernel panics since we set up netconsole. I also don't know how much a NIC is affected by a panic. I tried to find something in the kernel source. At least the panic message has the log level KERN_EMERG so something should go through. I guess it is a matter of experience. I'd start with log level 7 which can be reduced any time. Cheers, Henning _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
