Hide Forgot
Description of problem: logs in /var/log only show messages from a very late stage in the boot process all early boot messages are in the kernel ringbuffer (dmesg) but are never written to any file. worse off, when started with systemd.log_level=debug, they are so many that the ringbuffer cannot fit them, making it impossible to debug the first log messages. boot.log is ALWAYS empty too. this is contrary to old system behavior and to systemd's alleged feature of saving all boot logs to a file.
Created attachment 534920 [details] precise log output written by rsyslog when told to write ALL facilities and priorities to a single file
(In reply to comment #0) > all early boot messages are in the kernel ringbuffer (dmesg) but are never > written to any file. By default, rsyslog only stores the kernel messages from the ringbuffer. You can change that in /etc/rsyslog.conf using: $KLogPermitNonKernelFacility on Reassigning to rsyslog to consider the possibility of changing the default. > worse off, when started with systemd.log_level=debug, > they are so many that the ringbuffer cannot fit them, making it impossible to > debug the first log messages. That's why I always suggest log_buf_len=1M together with systemd.log_level=debug.
(In reply to comment #0) > Description of problem: > > logs in /var/log only show messages from a very late stage in the boot process Which logs? Testing on f16 and f17 shows all the early messages from the ringbuffer are stored in /var/log/messages. Some of the messages have 'debug' severity and are not included. On f17, this roughly matches the dmesg output regardless of '$KLogPermitNonKernelFacility'. On f16, this is similar except there appear to be some debug messages in the dmesg output from systemd. These are only logged with '$KLogPermitNonKernelFacilit on'. > all early boot messages are in the kernel ringbuffer (dmesg) but are never > written to any file. worse off, when started with systemd.log_level=debug, > they are so many that the ringbuffer cannot fit them, making it impossible to > debug the first log messages. > > boot.log is ALWAYS empty too. I haven't observed this. > this is contrary to old system behavior and to systemd's alleged feature of > saving all boot logs to a file. Michal, though probably harmless, I'm not convinced to include this directive in the default configuration.
(In reply to comment #3) > (In reply to comment #0) > > boot.log is ALWAYS empty too. boot.log gets written by plymouth. > Michal, though probably harmless, I'm not convinced to include this directive > in the default configuration. Right. Don't. Since in F17 systemd does not use the kernel buffer by default anymore (it uses the journal instead), the directive is not necessary. In F16 the users can set $KLogPermitNonKernelFacility if needed. And if they increase the systemd log level, they can increase the kernel buffer length too.