Notes on reading kernel messages
Note the following points when reading kernel messages on various platforms.
The kernel usually sends log messages to a special file (
/proc/kmsgon Linux). The
file()driver reads log messages from such files. The AxoSyslog application can periodically check the file for new log messages if the
follow-freq()option is set.
On Linux, the
klogddaemon can be used in addition to AxoSyslog to read kernel messages and forward them to
klogdused to preprocess kernel messages to resolve symbols and so on, but as this is deprecated by
ksymoopsthere is really no point in running both
klogdand AxoSyslog in parallel. Also note that running two processes reading
/proc/kmsgat the same time might result in dead-locks.
When using AxoSyslog to read messages from the
/proc/kmsgfile, AxoSyslog automatically disables the
follow-freq()parameter to avoid blocking the file.
To read the kernel messages on HP-UX platforms, use the following options in the source statement:
file("/dev/klog" program-override("kernel") flags(kernel) follow-freq(0));