Hello!
Grafana are installed from rpm.
I changed log level in /etc/grafana/grafana.ini:
[log]
# Either “console”, “file”, “syslog”. Default is console and file
# Use space to separate multiple modes, e.g. “console file”
;mode = console file
# Either "trace", "debug", "info", "warn", "error", "critical", default is "info"
;level = debug
# optional settings to set different levels for specific loggers. Ex filters = sqlstore:debug
;filters = context:trace
# For "console" mode only
[log.console]
;level = debug
# log line format, valid options are text, console and json
;format = console
# For "file" mode only
[log.file]
;level = debug
# log line format, valid options are text, console and json
;format = text
But after Grafana restart logging still with info level.