osm(7) osm(7)
NAME
osm - Operating System Messages (OSM)
DESCRIPTION
The kernel and drivers store their messages in the /dev/osm console
ring buffer. These can be unstructured texts as they appear on the
console or structured CMN kernel and DRV driver messages. As of Reli-
ant UNIX V5.44, the kernel and driver messages are no longer dupli-
cated in /dev/log. The console ring buffer is 10,000 bytes large and
should primarily record the messages that arise before Logging V3.0 or
the syslogd daemon starts. It is only if more than 10,000 bytes of
messages arise before logging starts - depending on the hardware con-
figuration - that messages may be lost through the cyclical overwrit-
ing of the console ring buffer.
The syslogd daemon is started by the /etc/rc2.d/S06log3 script when
multiuser mode is initiated and begins immediately to read and log
/dev/osm2, i. e. all messages written to /dev/osm from this time on
are logged by the syslogd daemon. All messages written previously to
/dev/osm have been collected in the main memory by the kernel and sent
to the daemon with /dev/log when the syslogd daemon was started.
Almost the entire main memory is available for storing messages, which
means that no messages can be lost.
The osmd daemon is started [see osmd(1M)] by the /etc/rc2.d/S09osm
script [see S09osm(1M)] when multiuser mode is initiated. The daemon
then reads /dev/osm and creates log files. The console ring buffer is
read from the beginning and further messages are awaited.
The osmd daemon creates a cycle of three files, by default, under
/etc/.osm[.MM-DD-hh:mm], whereby the maximum size of each file is
5 MB. The messages are always written to the file without the suffix.
If the maximum size of this file will be exceeded by the next entry,
the file is assigned a suffix made up of date and time and a new file
is created without the suffix. The messages are written to this new
file. If the number of files in the cycle will consequently be
exceeded, the oldest files are deleted (generally one file unless the
number of files belonging to the cycle has been reduced). The defaults
for the osmd daemon can be overridden by values from the
/etc/default/osm.conf configuration file [see osm.conf(4)]. The signal
1 (SIGHUP) must be sent to the osmd daemon to enable it to load the
modified content of the /etc/default/osm.conf configuration file.
_____________________________________________________________________________
| | osmd | Configuration file | |
| | defaults | /etc/default/osm.conf | Range |
|_____________|___________|___________________________|______________________|
| File name | /etc/.osm| PROTOCOL=/var/adm/log/osm| Arbitrary |
| No. cycles | 3 | MAX=3 | 2 - 100 |
| Maximum size| 5 MB | SIZE=5120000 | 10 KB - ulimit value|
|_____________|___________|___________________________|______________________|
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osm(7) osm(7)
The configuration file supplied ensures that the root file system can
no longer overflow. The settings in the configuration file are not
overwritten with an update installation.
Invoke the following command for a chronological listing of the proto-
col for all files in the cycle:
cat `ls -tr /var/adm/log/osm*` | pg
FILES
/dev/osm
console ring buffer for kernel and driver messages
/etc/default/osm.conf
configuration file for the osmd daemon
/etc/default/osm.filter
filter file
/etc/.osm[.MM-DD-hh:mm]
log files
/var/adm/log/osm[.MM-DD-hh:mm]
log files
SEE ALSO
osm(1M), osmd(1M), syslogd(1M), osm.conf(4), log(7).
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