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ml"><B>Installing=20
        a new kernel RPM</B></A>=20
        <LI><A =
href=3D"http://www.yolinux.com/TUTORIALS/index.html"><B>YoLinux=20
        Tutorials Index</B></A> </LI></UL><A name=3DMONITOR></A>
      <P>
      <HR SIZE=3D5>

      <TABLE cellSpacing=3D0 cellPadding=3D2 width=3D"100%" border=3D0>
        <TBODY>
        <TR bgColor=3D#ffcc33>
          <TD><B><BIG>Monitoring the =
system:</BIG></B></TD></TR></TBODY></TABLE>
      <P><B>Basic command line:</B>=20
      <DL>
        <DD>
        <TABLE>
          <TBODY>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dpstree">=
pstree</A>=20
            </TD>
            <TD>Processes and parent-child relationships</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dtop">top=
</A>=20
            </TD>
            <TD>Show top processes</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dps">ps=20
              -auxw</A> </TD>
            <TD>process status</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dvmstat">=
vmstat</A>=20
            </TD>
            <TD>Monitor virtual memory</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dfree">fr=
ee</A>=20
            </TD>
            <TD>Display amount of free and used memory in the system. =
(Also:=20
              <TT>cat /proc/meminfo</TT>)</TD></TR>
          <TR>
            <TD><A =
href=3D"http://web.hexapodia.org/~adi/pmap.c">pmap</A> </TD>
            <TD>Display/examine memory map and libraries (so). Usage: =
<TT>pmap=20
              <I>pid</I></TT></TD></TR>
          <TR>
            <TD>cat /proc/sys/vm/freepages</TD>
            <TD>Display virtual memory "free pages". <BR>One may=20
              increase/decrease this limit: <TT>echo 300 400 500 &gt;=20
              /proc/sys/vm/freepages</TT></TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Duname">u=
name=20
              -a</A> </TD>
            <TD>print system information</TD></TR>
          <TR>
            <TD>cat /proc/version </TD>
            <TD>Display Linux kernel version in use.</TD></TR>
          <TR>
            <TD>cat /etc/redhat-release </TD>
            <TD>Display Red Hat Linux Release. (also=20
<TT>/etc/issue</TT>)</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Duptime">=
uptime</A>=20
            </TD>
            <TD>Tell how long the system has been running. Also number =
of=20
              users and system's load average.</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dw">w</A>=
=20
            </TD>
            <TD>Show who is logged on and what they are doing.</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dlsmod">/=
sbin/lsmod</A>=20
            </TD>
            <TD>List all currently loaded kernel modules.<BR>Same as =
<TT>cat=20
              /proc/modules</TT></TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Drunlevel=
">/sbin/runlevel</A>=20
            </TD>
            <TD>Displays the system's current runlevel.</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dhostname=
">hostname</A>=20
            </TD>
            <TD>Displays/changes the system's node name. (Must also =
manually=20
              change hostname setting in =
<TT>/etc/sysconfig/network</TT>.=20
              Command will change entry in =
<TT>/etc/hosts</TT>)</TD></TR>
          <TR>
            <TD vAlign=3Dtop>service</TD>
            <TD vAlign=3Dtop>Red Hat/Fedora command to display status of =
system=20
              services.<BR>Example: <TT>service =
--status-all</TT><BR>Help:=20
              <TT>service =
--help</TT></TD></TR></TBODY></TABLE></DD></DL>
      <P><B>GUI/Graphical:</B>=20
      <DL>
        <DD>
        <TABLE>
          <TBODY>
          <TR>
            <TD><A=20
              =
href=3D"http://freshmeat.net/projects/gnome-system-monitor/">gnome-system=
-monitor</A>=20
            </TD>
            <TD>Operating system monitor and usage graphing.</TD></TR>
          <TR>
            <TD><A=20
              =
href=3D"http://web.wt.net/~billw/gkrellm/gkrellm.html">gkrellm</A>=20
            </TD>
            <TD>Graphical system monitor. (Additional RPM package:=20
          gkrellm)</TD></TR>
          <TR>
            <TD><A href=3D"http://user.tninet.se/~uhu537u/">ps3</A> =
</TD>
            <TD>3D load meter. Very cool 3-D graphics.</TD></TR>
          <TR>
            <TD><A href=3D"http://xosview.sourceforge.net/">xosview</A> =
</TD>
            <TD>Operating system monitor: load, memory, swap, net, disk, =

          ...</TD></TR></TBODY></TABLE></DD></DL>
      <P><B>List of tools:</B>=20
      <UL>
        <LI><A=20
        =
href=3D"http://www.ibiblio.org/pub/Linux/system/status/!INDEX.html">tools=
=20
        for finding the status of your system</A> </LI></UL><A =
name=3DPROCESSES></A>
      <P>
      <HR SIZE=3D5>

      <TABLE cellSpacing=3D0 cellPadding=3D2 width=3D"100%" border=3D0>
        <TBODY>
        <TR bgColor=3D#ffcc33>
          <TD><B><BIG>Process =
Management:</BIG></B></TD></TR></TBODY></TABLE>
      <P>The basic monitoring commands such as <TT>pstree</TT> and =
<TT>ps=20
      -auxw</TT> and <TT>top</TT> will inform you of the processes =
running on=20
      your system. Sometimes a process must be terminated. To terminate =
a=20
      process:=20
      <OL>
        <LI>Identify the process:=20
        <UL>
          <LI><TT>pstree -p</TT> <BR>OR=20
          <LI><TT>ps -auxw</TT> <BR>OR=20
          <LI><TT>top</TT> </LI></UL>
        <LI>Kill the process:=20
        <UL>
          <LI><TT>kill &lt;<I>process-id-number</I>&gt;</TT>=20
          <LI><TT>killall &lt;<I>command-name</I>&gt;</TT> =
</LI></UL></LI></OL>
      <P>This will perform an orderly shutdown of the process. If it =
hangs give=20
      a stronger signal with: <TT>kill -9 =
&lt;<I>process-id-number</I>&gt;</TT>.=20
      This method is not as sanitary and thus less preferred.=20
      <P>A signal may be given to the process. The program must be =
programmed to=20
      handle the given signal. See <TT>/usr/include/bits/signum.h</TT> =
for a=20
      full list. For example, to restart a process after updating it's=20
      configuration file, issue the command <TT>kill -HUP=20
      &lt;<I>process-id-number</I>&gt;</TT>=20
      <P>In the previous example, the <B>HUP</B> signal was sent to the =
process.=20
      The software was written to trap for the signal so that it could =
respond=20
      to it. If the software (command) is not written to respond to a =
particular=20
      signal, then the sending of the signal to the process is futile.=20
      <P>Identify all known signals: <TT><A=20
      =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dfuser">f=
user</A>=20
      -l</TT>=20
      <P>
      <H4>Process Management GUI Tools:</H4>
      <UL>
        <LI><A href=3D"http://xosview.sourceforge.net/">xosview</A>: =
Oldie but=20
        goodie.=20
        <LI>gnome-system-monitor=20
        <LI>ksysguard (comes with SuSE)=20
        <LI><A =
href=3D"http://www.student.nada.kth.se/~f91-men/qps/">QPS</A> (See=20
        below) </LI></UL>
      <P><B>QPS: </B>
      <DL>
        <DD>Also see the <A=20
        href=3D"http://www.student.nada.kth.se/~f91-men/qps/">GUI tool =
QPS</A>.=20
        (Handles MOSIX cluster) This tool is outstanding for monitoring, =

        adjusting nice values (priorities), issue signals to the =
process, view=20
        files the process is using, the memory, environmnet variables =
and=20
        sockets the process is using. RPM available from this site. It =
is so=20
        simple to use, no instructions are necessary. It can monitor a =
program=20
        to make sure it isn't doing something bad. It is also reverse =
engineer=20
        what applications are doing and the environments under which =
they run. I=20
        love this tool!!=20
        <P>
        <UL>
          <LI><A =
href=3D"http://www.student.nada.kth.se/~f91-men/qps/">QPS home=20
          page: 1.9.7</A> [<A=20
          href=3D"ftp://ptah.lnf.kth.se/pub/qps/">Downloads</A>]=20
          <LI><A href=3D"http://qps.kldp.net/">QPS: newer version =
1.9.8-1.9.14</A>=20
          - [<A=20
          =
href=3D"http://rpmseek.com/rpm-pl/qps.html?hl=3Dcom&amp;cx=3D857:Q:0">Dow=
nload=20
          RPMs for Fedora 4, 5, SuSE, Mandriva</A>] <BR>(SuSE version =
9.3 ships=20
          with a brokern QPS. Download a working version at link above.) =

</LI></UL>
        <P>Note: The RPM provided was compiled for RedHat 7.x. For =
RedHat 8.0+=20
        one must install the appropriate QT library RPMs to satisfy=20
        dependencies: <PRE>   rpm -ivh qt2-2.3.1-8.i386.rpm =
qt2-Xt-2.3.1-8.i386.rpm qt2-devel-2.3.1-8.i386.rpm =
qt2-static-2.3.1-8.i386.rpm
</PRE>Then install qps: <TT>rpm -ivh qps-1.9.7-5.i386.rpm</TT>=20
        <P>Note Fedora Core 3: <TT>rpm -ivh qt2-2.3.1-8.i386.rpm=20
        qps-1.9.7-5.i386.rpm</TT> <BR>These older RH 8.0 and 7 binary =
release=20
        rpms even work on my AMD64 Fedora Core 3 x86_64 OS system.=20
        <P>Configuring QPS to run applications against a process: Select =

        "Command" + "Edit Commands..." + "Add..."=20
        <UL>
          <LI>Description: GDB <BR>Command Line: <TT>xterm -T "GDB %C" =
-e gdb -d=20
          /<I>directory-where-source-code-is-located</I> --pid=3D%p</TT> =

          <LI>Description: gdb <BR>Command Line: <TT>xterm -T "gdb %c =
(%p)" -e=20
          gdb /proc/%p/exe %p &amp;</TT> <BR>(As issued in RPM) <BR><A=20
          =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dgdb">gdb=
=20
          man page</A>=20
          <LI>Description: strace <BR>Command Line: <TT>xterm -T "strace =
%c=20
          (%p)" -e sh -c 'strace -f -p%p; sleep 10000'&amp;</TT> =
<BR>(show=20
          process system calls and signals. Try it with the process qps =
itself.)=20
          <BR>Show output written by process: <BR><TT>xterm -T "strace =
%c (%p)"=20
          -e sh -c 'strace -f -q -e trace=3Dwrite -p%p; sleep =
10000'&amp;</TT>=20
          <BR><A=20
          =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dstrace">=
strace=20
          man page</A>=20
          <LI>Description: truss (Solaris command) <BR>Command Line: =
<TT>xterm=20
          -T "truss %C (%p) -e sh -c 'truss -f -p %p; sleep =
1000'&amp;</TT>=20
        </LI></UL></DD></DL>
      <P><B>IPCs: Semaphores, Shared Memory and Queues</B>=20
      <P>
      <DL>
        <DD>Note that some processes may use Linux InterProcess =
Communication or=20
        IPC (semaphores, shared memory or queues) which may need to be =
cleaned=20
        up manually:=20
        <OL>
          <LI>Identify the semaphores: <TT><A=20
          =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dipcs">ip=
cs</A></TT>=20
          <BR><TT>ipcs -q</TT> List share queues. <BR><TT>ipcs -m</TT> =
Shared=20
          memory. <BR><TT>ipcs -s</TT> List Semaphores.=20
          <LI>Remove the semaphores: <TT><A=20
          =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dipcrm">i=
pcrm</A>=20
          -s &lt;<I>ipcs id</I>&gt;</TT> </LI></OL>
        <P>Example: If you are running Apache, you may see the =
following:=20
        <DL>
          <DD><PRE><B>[root@node DIR]#</B>  ipcs -m                   =20

------ Shared Memory Segments --------
key       shmid     owner     perms     bytes     nattch    status     =20
0x00000000 341504    nobody    600       46084     27        dest   =20
</PRE></DD></DL></DD></DL>
      <P><B>lsof - Processes attached to open files or open network =
ports:</B>=20
      <DL>
        <DD>The command <TT><A=20
        =
href=3D"http://node1.yo-linux.com/cgi-bin/man2html?cgi_command=3Dlsof">ls=
of</A></TT>=20
        shows a list of processes attached to open files or network =
ports.=20
        <UL>
          <LI>List processes attached to a given file: <TT>lsof=20
          <I>filename</I></TT>:=20
          <DL>
            <DD><PRE><B>[root@node DIR]#</B> lsof =
/var/log/mailman/qrunner
python  18538 mailman    4u   REG    3,5  657 486746 =
/var/log/mailman/qrunner
python  18578 mailman    6u   REG    3,5  657 486746 =
/var/log/mailman/qrunner
python  18579 mailman    6u   REG    3,5  657 486746 =