All *nix systems have six run levels.  Red Hat uses:
    0    Shut down all services and halt.
    1    Single-user mode.  Only the console is
         enabled.  The console user is
         automatically logged in as root.  No other
         connections are permitted.
    2    Multi-user without networking. Rarely used.
    3    Standard multi-user text mode operation.
    4    Not used.
    5    Standard multi-user operation with
        graphical login.
    6    Shut down all services and reboot.
Note:  Different Linux Distros switch run levels 3, 4, & 5 around.

-mj-
Eric "Shubes" wrote: 
Run levels 2 and 3 vary by distro in their interpretation.

I'm not positive, but I think that RH based distros might consider 3 to be
undefined (as is 4). What is considered as multi-user on RH is 2, while on
debian it's 3. Or something like that.

Can someone please explain in an understandable way what's what on which?

keith smith wrote:
  
I would have thought so too.  They were not set to run on runlevel 3.


*/Craig White <craigwhite@azapple.com>/* wrote:

    httpd/mysqld/smb should all run whether runlevel 3 or 5

    You aren't likely to see that much of a difference between the two
    runlevels until someone logs in - at which point, on runlevel 5, a whole
    lot more processes are started.

    until then, the major difference between the two will be found

    ps aux|grep gdm

    just to be sure though, I confirm...

    chkconfig --list [service]

    chkconfig --levels 2345 httpd on
    chkconfig --levels 2345 mysqld on
    chkconfig --levels 2345 smb on

    Craig

    On Sat, 2006-11-04 at 07:25 -0800, keith smith wrote:
    > After adding:
    >
    > [root@dev bin]# /sbin/chkconfig --level 3 httpd on
    > [root@dev bin]# /sbin/chkconfig --level 3 mysqld on
    > [root@dev bin]# /sbin/chkconfig --level 3 smb on
    > [root@dev bin]# /sbin/chkconfig --level 3 yum on
    >
    > - - - - - - - -
    > [root@dev bin]# free
    > total used free shared buffers
    > cached
    > Mem: 385772 311396 74376 0 71832
    > 177692
    > -/+ buffers/cache: 61872 323900
    > Swap: 666688 88 666600
    >
    > Not a real big diff.
    >
    > RunLevel 5 : 312956
    > RunLevel 3 : 311396
    >
    > It does seem more responsive......
    >
    > Keith
    >
    >
    >
    > "Eric \"Shubes\"" wrote:
    > keith smith wrote:
    > > When I execute runlevel it returns "3 5" - could it be
    > possible I'm
    > > running both?
    >
    > man runlevel
    >
    > > free:
    > > total used free shared buffers cached
    > > Mem: 385772 312696 73076 0 70856 176448
    > > -/+ buffers/cache: 65392 320380
    > > Swap: 666688 88 666600
    > >
    > > - - - - -
    > > [root@dev bin]# /sbin/telinit 3
    > > [root@dev bin]# free
    > >
    > > total used free shared buffers cached
    > > Mem: 385772 298428 87344 0 70896 175780
    > > -/+ buffers/cache: 51752 334020
    > > Swap: 666688 88 666600
    > >
    > > [root@dev bin]# /sbin/runlevel
    > > 5 3
    > >
    > > ------
    > >
    > > [root@dev bin]# /sbin/telinit 5
    > > [root@dev bin]# /sbin/runlevel
    > > 3 5
    > > [root@dev bin]# free
    > > total used free shared buffers cached
    > > Mem: 385772 312956 72816 0 71024 176468
    > > -/+ buffers/cache: 65464 320308
    > > Swap: 666688 88 666600
    > > [root@dev bin]#
    > >
    > > - - - - - - - -
    > >
    > > Looks like only 14M diff.
    > >
    > > runlevel 3 kills samba, mysql and httpd also. I would think
    > that would
    > > be worth a little also.
    > >
    > > - - - - - - -
    > >
    > > I would be interested in changing runlevel 3 to start samba,
    > mysql, and
    > > httpd. These are the ones I use all day.
    >
    > If you're running a RH-based distro, you can use the chkconfig
    > command to
    > change this, e.g.:
    > # chkconfig --level 235 samba on
    >
    > man chkconfig
    >
    > I'm not sure how to do this on debian boxen.
    >
    > > This has been most informative and interesting!
    > >
    > > Thnaks for your help,
    > > Keith
    > >
    > >