lkstlogd(8)

NAME
lkstlogd - Linxu Kernel State Tracer logging utility.

SYNOPSIS
lkstlogd [-a] [-b buffer_size[K|M]] [-l limit_size[K|M]] [-n number] [-f log_file_name] [-hv]

DESCRIPTION
lkstlogd supports to analyze faults which do not crash kernel; typically faults as follows:

A certain application can never start.
A certain daemon process ends suddenly, but the cause is unknown.
lkstlogd provides functions as follows: When a specific signal is sent to lkstlogd, lkstlogd starts to write event logs, which is recorded by lkst, to a specified file. And lkstlogd continues writing the file until the signal is sent again. In addition, when another special signal is sent, lkstlogd saves currently writing file and creates new one.

OPTIONS

-a  Start to write event logs to a file with starting lkstlogd.

-b buffer_size[K|M]
    Specify buffer size to create at initialization. buffer_size is followed by K and M suffixes representing size in Kilo bytes and in Mega bytes, respectively. (Default 2MByte)

-l limit_size[K|M]
    Specify a maximum size of log file in byte. If the file size has reached the maximum size, lkstlogd rewinds the write pointer to head of the file. limit_size is also followed by K and M suffixes representing size in Kilo bytes and in Mega bytes, respectively. The default size if 10MByte.

-n number
    Specify number of buffer (for each CPU) to create at initialization. (Default 2)

-f log_file_name
    Specify log file name.

-h  Print help message.

-v  Print version of this command.

OUTPUT FORMAT
Same as output of lkstbuf command.

SIGNALS
lkstlogd receives signals. To send signal to lkstlogd, use `kill` command as follow.

    kill -SIGNAL `cat /var/run/lkstlogd.pid`

SIGHUP
    Re-initialize lkstlogd. All the opened files are closed, and all child processes are terminated. Then lkstlogd is restarted.

SIGTERM
    Terminate lkstlogd.

SIGUSR1
    Start to write event logs to a file. When lkstlogd receives it again, lkstlogd stops writing logs.

SIGUSR2
    Change a file to write event logs.

FILES

/var/log/lkst/sebuf<cpu_number>.<serial_number>
    lkstlogd writes event logs to different files for each CPU. In addition, when lkstlogd receives SIGUSR2, saves currently writing file, and create new file of which serial_number is increased by 1, and start writing to the file. This file can be changed by using -f option.

/var/run/lkstlogd.pid
    This file holds process ID of lkstlogd. lkstlogd checks presence of this file at first. If it is, lkstlogd exits as error.

/etc/sysconfig/lkstlogd
    Configuration file for lkstlogd. This file format is shown as follows:

    # comment
    LKSTLOGDOPTION="-l 8388608"
    # at line head shows this line is comment sentence. In LKSTLOGDOPTION, start options of lkstlogd are written. This file is read and interpreted by rc file at system initialization.

REFERENCES
ioctl(LKST_IOC_BUFFER_READ)(2), lkstbuf(8)