SSH Reference Manual

Destinations for Log Messages
The SSH2 component can log to the following destinations:
• A file configured with the LOGFILE parameter.
• An process-internal memory cache for log message (parameters LOGLEVELCACHE, LOGCACHESIZE)
• A device configured with the LOGCONSOLE parameter.
• An event collector process configured with the LOGEMS parameter.
By default, the SSH2 component logs messages only to the home terminal. Logging to a file or EMS is not enabled by
default. It is possible to log to multiple destinations. Which combination is best will depend on your operative
environment. The following shows some examples on how to combine the log destinations in different scenarios:
• Getting used to SSH2, "experimenting": It may be easiest to start SSH2 with the default settings. In that case
SSH2 will issue log messages to the home terminal only, making it easy to view the messages. Note that you
cannot start the SSH2 component NOWAIT this way. It may be helpful to raise the LOGLEVEL to 100 in that
case.
LOGFILE *
LOGEMS *
LOGLEVELCONSOLE 100
LOGCONSOLE %
• Log to EMS and only log startup and severe messages:
LOGFILE *
LOGCONSOLE *
LOGEMS $0
LOGLEVELEMS 30
• Log normal operations to a file and startup and severe messages to EMS:
LOGCONSOLE *
LOGFILE $vol.subvol.logfile
LOGLEVELFILE 50
LOGEMS $0
LOGLEVELEMS 30
• Log normal operations to a file and startup and severe messages to EMS, log detail information to log cache
and write content to the log file via SSHCOM command FLUSH LOGCACHE only after specific events:
LOGCONSOLE *
LOGFILE $vol.subvol.logfile
LOGLEVELFILE 50
LOGEMS $0
LOGLEVELEMS 30
LOGLEVELCACHE 85
Writing to the log cache causes the least overhead. If detailed log messages need to be analyzed, then it is often best to
set the value of LOGLEVELCACHE to a higher value (e.g. via SSHCOM command SET LOGLEVELCACHE) and
leave the parameter LOGLEVELFILE at the default level. After the event occurred that is of interest the messages in the
log cache should then be written to the log file using SSHCOM command FLUSH LOGCACHE (see section "SSHCOM
Command Reference"). The SSHCOM command ROLLOVER LOGFILE can be used to force the log file rollover
allowing to keep the log file small.
HP NonStop SSH Reference Manual Monitoring and Auditing • 309