Logging

crimson-osd uses the Seastar logging utility.

See src/common/dout.h for the mapping between Ceph logging levels to the severity levels in Seastar. For instance, messages sent to derr will be issued using logger::error(), and the messages with a debug level greater than 20 will be issued using logger::trace().

Table 1 shows the log level mapping for Ceph to Seastar.
Table 1. Log level mapping
Ceph Seastar
< 0 error
0 warn
[1, 6) info
[6, 20] debug
> 20 trace
Note: crimson-osd does not send log messages directly to a specified log_file. It writes the logging messages to stdout and/or syslog. This behavior can be changed using --log-to-stdout and --log-to-syslog command line options. By default, --log-to-stdout is enabled, and --log-to-syslog is disabled.