HP-UX Reference (11i v3 07/02) - 1M System Administration Commands N-Z (vol 4)

n
nettl(1M) nettl(1M)
is specified then filter status is displayed for all the subsystems that currently support
filters as listed above.
-removefilter all
-removefilter
subsystem ...
(Abbr.: -rfl)
Used as a standalone option.
This option is used to remove filter expressions for subsystems that have been set with the
setfilter command. If the attribute all is specified then filters are removed for all
the subsystems that currently support filters as listed above.
Trace Memory Management
Memory used for tracing is made up of a circular linked list of trace buffers, each of which holds the trace
messages until they are written to the file. Trace messages are written to a buffer until it is filled, after
which the buffer is written to the file as a whole. While the buffer is being written to the file, the next
buffer in the list is used to hold the incoming trace messages. If no buffer is free to hold the incoming trace
messages, the messages will be dropped. Under this condition, additional trace buffers can be allocated if
the max_mem value is specified for -mem option.
To achieve best tracing performance, the tracing algorithm imposes the following constraints:
a) Since a buffer is written to the file as a whole, the individual file size should be at least the buffer
size.
b) The additional amount of memory that can be allocated under heavy traffic given by (max_mem -
init_mem) should be at least the buffer size.
where: buffer size =
MIN( init_mem/4, 32 MB )
Refer to examples 10 and 11 for further details.
Data File Management
Data files created by the tracing and logging facility require special handling by the facility that you must
be aware of. When files are created, they have the suffix .LOG000 or .TRC000
appended to them,
depending on whether they are log or trace files, respectively. This scheme is used to keep the files distinct
for cases where you specify the same name in both places. Also, the files implement a type of circular
buffer, with new data always going into the file appended with
.LOG000 or
.TRC000. When a
logname
.LOG000 or tracename.TRC000 file is full, each log or trace is renamed to the next higher
number in its sequence; that is, a file with sequence number N is renamed as a file with sequence number
N+1 and a new file named logname.LOG000 or tracename.TRC000 is created. The number of files that
can exist simultaneously on the system can be specified by the
-n option.
Note: The file name prefix (logname or tracename) specified by the user must not exceed eight charac-
ters so that the file name plus suffix does not exceed fourteen characters. Longer names are trun-
cated. To see the actual name of the trace or log file, use the
nettl -status all command.
Console Logging
Console logging is used to display significant log events on the system console. The values in the
/etc/nettlgen.conf file determine if console logging is to be started and the entries in the
/var/adm/conslog.opts file determine what log messages will be reported to the console. The
nettlconf command can be used to configure and maintain the information in the
/etc/nettlgen.conf file (see nettlconf(1M)). If changes are made to these files, nettl must be
stopped and restarted for the new information to take effect.
All log messages written to the console as a result of this configuration information are in a special short
form. If more information is desired on the console, the
netfmt formatter can be used to direct output to
the console device. This may be most useful in an X windows environment.
Console logging may be disabled if conservation of system resources is valued more than notification of log
events.
Trace Fil ter s
Trace filters are a filter criteria applied on trace packets before actually capturing them. The filter criteria
is an expression consisting of a combination of header fields, (link level, TCP/IP and so on) specified in the
filter configuration file. Packets that pass the filter criteria are captured; all other packets are discarded.
HP-UX 11i Version 3: February 2007 − 7 − Hewlett-Packard Company 55