dfs@doe.carleton.ca (David F. Skoll) (04/25/91)
I use a Sun system, and I've never heard of "Run-Level." What is it? -- David F. Skoll
weimer@garden.ssd.kodak.com (Gary Weimer (253-7796)) (04/26/91)
In article <dfs.672587346@pulaski>, dfs@doe.carleton.ca (David F. Skoll) writes: |> I use a Sun system, and I've never heard of "Run-Level." |> |> What is it? A brief description (since I've only had brief exposure to it...) BSD Unix (?) has three "run levels": Single-user, Multi-user and Halt. Usually we say the system is: in Single-user mode in Multi-user mode Down ( 1/2 :-) ) System V (?) Unix has many levels: 0 == Halt 3 == normal Multi-user mode others (this is were it gets brief :-) ) weimer@ssd.kodak.com ( Gary Weimer )
prl@iis.ethz.ch (Peter Lamb) (04/26/91)
dfs@doe.carleton.ca (David F. Skoll) writes: >I use a Sun system, and I've never heard of "Run-Level." >What is it? Since I looked it up, it seems that it's a SysV term describing the current state of init. I've been told that BSD-derived Unixes don't have this, but they do have two (major) states in init, which exactly correspond to two of the SysV run levels. If I move into pedantic mode, Sun (and other BSD-ish) Unices do have a run level, and the two run levels are single-user and multiuser mode. And there is not an easy way to discover which mode you are in. -- Peter Lamb uucp: uunet!mcsun!ethz!prl eunet: prl@iis.ethz.ch Tel: +411 256 5241 Integrated Systems Laboratory ETH-Zentrum, 8092 Zurich
dkeisen@leland.Stanford.EDU (Dave Eisen) (04/26/91)
In article <prl.672602340@iis> prl@iis.ethz.ch (Peter Lamb) writes: >If I move into pedantic mode, Sun (and other BSD-ish) Unices do have a run >level, and the two run levels are single-user and multiuser mode. > >And there is not an easy way to discover which mode you are in. > I don't know about BSD, but on our Xenix box "who am i" is an easy way to see whether the system is single-user. -- Dave Eisen dkeisen@leland.Stanford.EDU 1101 San Antonio Raod, Suite 102 (Gang-of-Four is being taken off the net) Mountain View, CA 94043 (415) 967-5644
jeffl@NCoast.ORG (Jeff Leyser) (04/27/91)
In post <1991Apr25.171617.13505@ssd.kodak.com>, weimer@ssd.kodak.com says:
!!
!!In article <dfs.672587346@pulaski>, dfs@doe.carleton.ca (David F. Skoll)
!!writes:
!!|> I use a Sun system, and I've never heard of "Run-Level."
!!|>
!!|> What is it?
!!
!!A brief description (since I've only had brief exposure to it...)
I deal with it daily.
!!
!!BSD Unix (?) has three "run levels": Single-user, Multi-user and Halt.
!!Usually we say the system is:
!! in Single-user mode
!! in Multi-user mode
!! Down ( 1/2 :-) )
!!
!!System V (?) Unix has many levels:
!! 0 == Halt
!! 3 == normal Multi-user mode
!! others (this is were it gets brief :-) )
Well, sorta. In SysV, init has 11 levels, numbered 0-6,a,b,c,S. Each
line in the /etc/inittab file has a corresponding set of identifiers,
e.g:
s2:23:wait:/etc/rc2 >/dev/console 2>&1 </dev/console
^^
run-levels
What each run-level "means" is somewhat vendor-specific (at least in SysVr3).
On our Motorola boxes, 0 and 6 are shutdown, 1 and S are single users, 2 is
multi-user, 3 is multi-user + RFS, and the rest are user defined. On
out NCR iron, 0 and S are single-user, 1 is multi-user, 2 is multi-user
+ RFS, 6 is shutdown, and the rest are user defined. Yes, I have often
shutdown the Motorola when trying to go single-user, and I have also
powered-down NCR boxes when they were only single-user, and hadn't been
sync'ed :^)
--
Jeff Leyser jeffl@NCoast.ORGnews@rushpc (News Administrator) (04/27/91)
>|> What is it? > >A brief description (since I've only had brief exposure to it...) > >System V (?) Unix has many levels: > 0 == Halt > 3 == normal Multi-user mode > others (this is were it gets brief :-) ) > >weimer@ssd.kodak.com ( Gary Weimer ) Correction. In System V Release 3.2: 0 == Halt 1 == Single user mode. Can be entered only from the console. 2 == Normal multi-user mode. 3 == Multi-user remote-file-sharing mode. 4 == User definable multi-user mode. 5 == Stop UNIX and enter firmware mode. 6 == Stop UNIX and reboot to the state defined in '/etc/inittab'. S == Single user mode. Terminal that executed this command becomes the console. -- John ---- Westminster Colorado ...uunet!rushpc!jjr
mike@bria.UUCP (Michael Stefanik) (04/28/91)
In an article, dkeisen@leland.Stanford.EDU (Dave Eisen) writes: >I don't know about BSD, but on our Xenix box "who am i" is an easy >way to see whether the system is single-user. The drag about XENIX is that there is the capability for who -r and other such command to work correctly. Too bad that the init under XENIX is too brain dead to add those entries to /etc/utmp when it fires up. Of course, an init that truly knows nothing about /etc/inittab should be pitched out the door anyway ... -- Michael Stefanik, MGI Inc, Los Angeles | Opinions stated are never realistic Title of the week: Systems Engineer | UUCP: ...!uunet!bria!mike ------------------------------------------------------------------------------- If MS-DOS didn't exist, who would UNIX programmers have to make fun of?
wes@harem.clydeunix.com (Wes Peters) (05/02/91)
In article <1991Apr25.171617.13505@ssd.kodak.com>, weimer@garden.ssd.kodak.com (Gary Weimer (253-7796)) writes: > BSD Unix (?) has three "run levels": Single-user, Multi-user and Halt. > Usually we say the system is: > in Single-user mode > in Multi-user mode > Down ( 1/2 :-) ) ^^^^^ Note that this is the natural state of all computers. :-) > System V (?) Unix has many levels: > 0 == Halt > 3 == normal Multi-user mode > others (this is were it gets brief :-) ) Not quite. Actually: 0 = Shutdown 1 = Single-user (roughly) 2 = Normal multi-user 3 = Another multi-user 4 = ????? 5 = Enter monitor program, if present 6 = Halt Init state 3 is used to run multi-user, but is differentiated from 2 because all the startup files can check to see what state you're in. For instance, you might define 2 to mean 'multiuser with network running' and 3 to mean 'multiuser with network shut off' or something similar. Getty, which starts the login process on terminals amongst other things, can tell what init state you're in also. Init state 5 goes into the setup program on my brother's 386, as close as you can get to a 'monitor' program. I don't have my System V manuals at hand, or I'd be able to flush this out a little more for you. Wes Peters -- #include <std/disclaimer.h> The worst day sailing My opinions, your screen. is much better than Raxco had nothing to do with this! the best day at work. Wes Peters: wes@harem.clydeunix.com ...!sun!unislc!harem!wes
alan@ukpoit.co.uk (Alan Barclay) (05/03/91)
In article <1991Apr25.171617.13505@ssd.kodak.com> weimer@ssd.kodak.com writes: > >System V (?) Unix has many levels: > 0 == Halt > 3 == normal Multi-user mode > others (this is were it gets brief :-) ) As with most unix things it really depends on how you've configured it but normally. 0 == Single user 1 == Multi user (no networking) 3 == Multi user (with networking) 6 == Shutdown 2,4,5 are left to be user defined. -- Alan Barclay iT | E-mail : alan@ukpoit.uucp Barker Lane | BANG-STYLE : .....!ukc!ukpoit!alan CHESTERFIELD S40 1DY | VOICE : +44 246 214241
rcd@ico.isc.com (Dick Dunn) (05/04/91)
alan@ukpoit.co.uk (Alan Barclay) writes about run levels: > As with most unix things it really depends on how you've configured it Yes, but there's a strong enough set of conventions in SysVland that it would be foolish to scramble them around--all you'll do is confuse people. Alan lists a set of run-level assignments I've never seen before, without saying what version of UNIX uses them. It's certainly not SysV...which confuses the issue since one of the newsgroups in the list is a SysV group. > 0 == Single user More conventionally, 0 is shutdown. > 1 == Multi user (no networking) If 0 is used for shutdown, 1 is normally single-user, and 2 is multi-user with no networking; then > 3 == Multi user (with networking) as Alan says. > 6 == Shutdown More conventionally, 6 is shutdown and reboot. -- Dick Dunn rcd@ico.isc.com -or- ico!rcd Boulder, CO (303)449-2870 ...If you plant ice, you're gonna harvest wind.
peter@ficc.ferranti.com (Peter da Silva) (05/04/91)
In article <1991May3.080600.6156@ukpoit.co.uk> alan@ukpoit.co.uk (Alan Barclay) writes: > 0 == Single user > 1 == Multi user (no networking) > 3 == Multi user (with networking) > 6 == Shutdown Normally, on System V/386: 0 == shutdown 1 == single user 2 == multi user 3 == networking I've used another System V system, but it had 0 == single user, 2 == multi user, and I added 3 == networking when I installed the network software. It didn't have a shutdown mode, per se, so long as power was up. -- Peter da Silva. `-_-' peter@ferranti.com +1 713 274 5180. 'U` "Have you hugged your wolf today?"
lothar@tmcsys.UUCP (L. Hirschbiegel) (05/04/91)
In article <1991May3.185400.4685@ico.isc.com> rcd@ico.isc.com (Dick Dunn) writes: >alan@ukpoit.co.uk (Alan Barclay) writes about run levels: > >> As with most unix things it really depends on how you've configured it > [ text deleted ] > >> 0 == Single user >More conventionally, 0 is shutdown. > >> 1 == Multi user (no networking) >If 0 is used for shutdown, 1 is normally single-user, and 2 is multi-user >with no networking; then >> 3 == Multi user (with networking) >as Alan says. > >> 6 == Shutdown >More conventionally, 6 is shutdown and reboot. >-- >Dick Dunn rcd@ico.isc.com -or- ico!rcd Boulder, CO (303)449-2870 > ...If you plant ice, you're gonna harvest wind. Its even more complicated under SystemV. From my manual pages for "init": SYNOPSIS /etc/init [0123456SsQqabc] There are also pseudostates a, b and c, which may be defined to run certain commands, but which do not cause the current runlevel to change. Sounds like an indexed runlevel to me :-) [ init 3.a ...] In addition there is a substantial diffence under SysV for runlevel 1 and runlevel S (both switch to single user state). Runlevel 1 can only be called from the system console (/dev/console, that is) and unmounts all filesystems except root. Runlevel S will keep all mounted filesystems and can be (in theory) called from any terminal. This terminal will then become the new system console. The biggest difference between runlevel 1 and S: in level 1 all processes not associated to the (real) system console will be killed, in level S only processes spawned by "init" are killed... Lothar Hirschbiegel -- --------------------------------------------------- | L. Hirschbiegel, AEG - A84, Frankfurt (Germany) | | email: unido!aega84!lh tel: -49-69-66414316 | ---------------------------------------------------
allbery@NCoast.ORG (Brandon S. Allbery KB8JRR/AA) (05/05/91)
As quoted from <230@harem.clydeunix.com> by wes@harem.clydeunix.com (Wes Peters): +--------------- | Not quite. Actually: | 0 = Shutdown | 1 = Single-user (roughly) | 2 = Normal multi-user | 3 = Another multi-user | 4 = ????? | 5 = Enter monitor program, if present | 6 = Halt +--------------- S is singleuser, 2 is multiuser without networking, 3 is multiuser with networking, 4 is unused. 5 may or may not be used, depending on Unix version. On the systems I have seen (Altos System V R3.1 and SCO UNIX) init 1 prepares the system for singleuser and does an "init S", and init 0 prepares the system for shutdown and does an "init 6" (which does "/etc/haltsys"). ++Brandon -- Me: Brandon S. Allbery Ham: KB8JRR/AA 10m,6m,2m,220,440,1.2 Internet: allbery@NCoast.ORG (restricted HF at present) Delphi: ALLBERY AMPR: kb8jrr.AmPR.ORG [44.70.4.88] uunet!usenet.ins.cwru.edu!ncoast!allbery KB8JRR @ WA8BXN.OH
dag@fciva.FRANKCAP.COM (Daniel A. Graifer) (05/05/91)
On our Prime EXL's, which run pretty much Plain Vanilla AT&T SysV 3.1 with some 3.2 extensions, we have: 0 - Shutdown System 1 - Single User Mode 2 - Normal Multi-User 3 - Multiuser + remote file sharing 4 - Undefined by system 5 - Shutdown and entire ROM diagnostic monitor 6 - Shutdown and reboot We've defined to state 4 to be system backup. A cron job in the wee dawn hours does a telinit 4 to start the backup process. We also cleanup the cron log at that time, since cron isn't running in state 4. We had to modify some of the scripts in rc2.d: who -r also contains the previous run level as well as the current one. Some of the scripts do nothing if the previous state isn't 0, eg. RMTMPFILES, and we wanted these to run coming out of state 4 as well. (With the backup automated, we've gone for months without rebooting, so lots of things such as tmp directories would fill up if we didn't clean them out as part of the nightly backup.) Dan -- Daniel A. Graifer Coastal Capital Funding Corp. Sr. Vice President, Financial Systems 7900 Westpark Dr. Suite A-130 (703)821-3244 McLean, VA 22102 uunet!fciva!dag fciva.FRANKCAP.COM!dag@uunet.uu.net
yee@aix01.aix.rpi.edu (Crimson Avenger) (05/06/91)
In the AT&T System 5, Release 4 book (Complete Reference by Obsorn McGraw-Hill) I think you mean system initialization state levels: State Function 0 Power off 1 Single User mode 2 Multi-user mode 3 Multi-user with network 4 Not used 5 Shutdown to ROM 6 Shutdown and Reboot s Single-user mode S Single-user with remote console With these definitions, I don't think some of them apply to PCs, I have a PC, but don't have unix up and running yet. I think a couple of those don't apply to the PC, like Power off, or Shutdown to ROM. I think in some machine, you can literally power off the computer via a software command. Not on PCs yet. Hope this helps, not sure. . -- -- Robert aka Crimson Avenger (yee@rpi.edu or crimson_avenger@mts.rpi.edu) Once a hacker, always a hacker. (usere3jp@rpitsmts.bitnet)
dcon@cbnewsc.att.com (david.r.connet) (05/10/91)
In article <602@fciva.FRANKCAP.COM> dag@fciva.UUCP (Daniel A. Graifer) writes: > >On our Prime EXL's, which run pretty much Plain Vanilla AT&T SysV 3.1 with >some 3.2 extensions, we have: > > 0 - Shutdown System > 1 - Single User Mode > 2 - Normal Multi-User > 3 - Multiuser + remote file sharing > 4 - Undefined by system > 5 - Shutdown and entire ROM diagnostic monitor > 6 - Shutdown and reboot > >We've defined to state 4 to be system backup. A cron job in the wee dawn >hours does a telinit 4 to start the backup process. We also cleanup the >cron log at that time, since cron isn't running in state 4. > From the AT&T SVR4 init(1M) man page 0 shut the machine down so it is safe to remove the power. Have the machine remove power if it can. 1 put the system in system administrator mode. All file systems are mounted. Only a small set of essential kernel processes are left running. This mode is for administrative tasks such as installing optional utility packages. All files are accessible and no users are logged in on the system. 2 put the system in multi-user mode. All multi-user environment terminal processes and daemons are spawned. This state is commonly referred to as the multi-user state. 3 start the remote file sharing processes and daemons. Mount and advertise remote resources. Run level 3 extends multi-user mode and is known as the remote-file-sharing state. 4 is available to be defined as an alternative multi-user environment configuration. It is not necessary for system operation and is usually not used. 5 Stop the UNIX system and go to the firmware monitor. 6 Stop the UNIX system and reboot to the state defined by the initdefault entry in /sbin/inittab. S,s enter single-user mode. When this occurs, the terminal which executed this command becomes the system console. This is the only run level that doesn't require the existence of a properly formatted /sbin/inittab file. If this file does not exist, then by default the only legal run level that init can enter is the single-user mode. When the system comes up to S or s, file systems for users' files are not mounted and only essential kernel processes are running. When the system comes down to S or s, all mounted file systems remain mounted, and all processes started by init that should only be running in multi-user mode are killed. In addition, any process that has a utmp entry will be killed. This last condition insures that all port monitors started by the SAC are killed and all services started by these port monitors, including ttymon login services, are killed. Other processes not started directly by init will remain running. For example, cron remains running. If a 0 through 6 is entered, init enters the corresponding run level. Run levels 0, 5, and 6 are reserved states for shutting the system down. Run levels 2, 3, and 4 are available as multi-user operating states. Dave Connet dcon@iwtng.att.com