trxsetbuf(1M)                                                 trxsetbuf(1M)

NAME
     trxsetbuf - define the internal system buffer size of tracex without a
     reboot

SYNOPSIS
     /opt/SItracex/bin/trxsetbuf buffersize

DESCRIPTION
     A data buffer is required in the operating system kernel for a tracex
     measurement. Using the trxsetbuf command, the buffer size of the
     current operating system can be changed to buffersize KB. No reboot is
     necessary when doing this. The changed buffer size is lost when the
     system is shut down.

     The tracex buffer is limited theoretically to a maximum of 32 Gbytes
     per CPU. A warning is issued if a buffer size is specified which
     exceeds 1 percent of the main memory size.

     Warning: If the measurement buffer is too large, the entire system
              performance is adversely affected.

NOTES
     Operating systems are supplied with 5 pages of buffer size by default.
     This is generally insufficient.

     The amount of main memory required for the tracex measurements depends
     on the number and clock frequency of the processors, the system load,
     and then the measurement points (events) to be logged.

     It is recommended to keep 128 Kbytes free per CPU initially. If there
     are measurement overruns, the buffer size can be increased gradually.

     The use of trxsetbuf is recommended if no or few reboots occur within
     a measurement sequence. If this is not the case, trxpatch(1M) can be
     used, which does however necessitate a reboot. Neither command is
     mutually exclusive.

     In multiprocessor systems, the microsecond timer used by tracex only
     functions approx. 3 minutes after the system is booted.

     Detailed instructions and, in particular, a description of all meas-
     urement points (events) known to tracex, as well as the format of the
     files, can be found in the /home/tracex/doc/trxman00 file.

SEE ALSO
     do.lev2(1M), trxchk(1M), trxeval(1M), trxout(1M), trxpatch(1M),
     trxproc(1M), entab(4), tracex(5).








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