Single-user mode - Revision history

Ninereasons: FixIt sometimes needed if console flagged as insecure

2006-05-10T20:12:35Z

FixIt sometimes needed if console flagged as insecure

Ninereasons: /* Reboot to single user mode */

2006-05-10T19:53:56Z

Reboot to single user mode

Ninereasons: expand on /Drop to single user mode/ and /Reboot to single user mode/

2006-05-10T19:10:07Z

expand on /*Drop to single user mode*/ and - Reboot to single user mode

Jimbo at 17:56, 5 December 2004

2004-12-05T17:56:19Z

Jimbo at 17:54, 5 December 2004

2004-12-05T17:54:22Z

Jimbo at 14:14, 29 October 2004

2004-10-29T14:14:36Z

New page

In '''single-user mode''', there is and can be only one login to the system, which will be the root user. This mode is needed if you want to unmount crucial partitions like '''/usr''' or '''/var''', ie for [[fsck]]-ing purposes. (You can [[fsck]] a mounted partition, but you CAN'T actually repair it while it's mounted - to repair it, you have to unmount it first and THEN [[fsck]] it.)

One way to drop to single-user mode is by typing '''init 1''' as [[root]]. WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.

[[Category:Common Tasks]]

@@ Line 1: / Line 1: @@
 In '''single-user mode''', there is and can be only one login to the system, which will be the root user.  This mode is needed if you want to unmount crucial partitions like '''/usr''' or '''/var''', ie for [[fsck]]-ing purposes.  (You can [[fsck]] a mounted partition, but you CAN'T actually repair it while it's mounted - to repair it, you have to unmount it first and THEN [[fsck]] it.)
-The second CD in the FreeBSD set is a FixIt disk that boots you into single-user mode, and you'll need to do that if something truly terrible happens.  Ordinarily though, if something merely awful happens (like, you mess up your kernel, you delete or mangle your <code>passwd</code> files, your /[[etc/fstab]] doesn't work), you'll be put into single user mode automatically, enabling you to fix the problem, in which case you'll be helpfully prompted to hit Enter for a shell prompt.
+The second CD in the FreeBSD set is a FixIt disk that boots you into single-user mode, and you'll need to do that if something truly terrible happens (you've used /[[etc/ttys]] to flag your physical console as ''insecure'' and your root password doesn't work after something awful happens).  Ordinarily though, if something merely awful happens (like, you mess up your kernel, you delete or mangle your <code>passwd</code> files, your /[[etc/fstab]] doesn't work), you'll be put into single user mode automatically, enabling you to fix the problem, in which case you'll be helpfully prompted to hit Enter for a shell prompt.
 ==Drop to single user mode==

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   shutdown -r
-Versions 5.x and 6.x offer a ''beastie-start'' boot menu with various loader options.  For example, number 4 is "boot into single user mode" and 6 is "escape to command prompt".  FreeBSD 7.x currently doesn't have this menu by default, and 4.x and prior don't have it at all.   In those cases, press the space bar to get the command prompt.  At the prompt type:
+In the bootup process, FreeBSD 5.x and 6.x offer a ''beastie-start'' boot menu with a few simple loader options.  For example, number 4 is "boot into single user mode" and 6 is "escape to command prompt".  FreeBSD 7.x currently doesn't have this menu by default, and 4.x and prior don't have it at all.   In those cases, press the space bar to get the command prompt.  At the loader prompt type:
   boot -s
-To attempt to enter multi-user mode, you can <code>reboot</code>, or press <code>^D</code> (''Ctrl+d''), or type:
+If you are in single user mode, to attempt to enter multi-user mode you can <code>reboot</code>, or press <code>^D</code> (''Ctrl+d''), or type:
   exit
 [[Category:Common Tasks]] [[Category:FreeBSD Terminology]]

@@ Line 1: / Line 1: @@
 In '''single-user mode''', there is and can be only one login to the system, which will be the root user.  This mode is needed if you want to unmount crucial partitions like '''/usr''' or '''/var''', ie for [[fsck]]-ing purposes.  (You can [[fsck]] a mounted partition, but you CAN'T actually repair it while it's mounted - to repair it, you have to unmount it first and THEN [[fsck]] it.)
-One way to drop to single-user mode is by typing [[init|init 1]] as [[root]].  WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.
+The second CD in the FreeBSD set is a FixIt disk that boots you into single-user mode, and you'll need to do that if something truly terrible happens.  Ordinarily though, if something merely awful happens (like, you mess up your kernel, you delete or mangle your <code>passwd</code> files, your /[[etc/fstab]] doesn't work), you'll be put into single user mode automatically, enabling you to fix the problem, in which case you'll be helpfully prompted to hit Enter for a shell prompt.
-Also, the second CD in the FreeBSD set is a FixIt disk that boots you into single-user mode.
+==Drop to single user mode==
 [[Category:Common Tasks]] [[Category:FreeBSD Terminology]]

@@ Line 1: / Line 1: @@
 In '''single-user mode''', there is and can be only one login to the system, which will be the root user.  This mode is needed if you want to unmount crucial partitions like '''/usr''' or '''/var''', ie for [[fsck]]-ing purposes.  (You can [[fsck]] a mounted partition, but you CAN'T actually repair it while it's mounted - to repair it, you have to unmount it first and THEN [[fsck]] it.)
-One way to drop to single-user mode is by typing '''init 1''' as [[root]].  WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.
+One way to drop to single-user mode is by typing [[init|init 1]] as [[root]].  WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.
 [[Category:Common Tasks]] [[Category:FreeBSD Terminology]]

← Older revision		Revision as of 17:54, 5 December 2004
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	One way to drop to single-user mode is by typing '''init 1''' as [[root]]. WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.		One way to drop to single-user mode is by typing '''init 1''' as [[root]]. WARNING: you'd better be physically logged in at a console when you do this, not shelled in across the network, because when you drop to single-user mode on a box, that box's network capability goes AWAY.

−	[[Category:Common Tasks]]	+	[[Category:Common Tasks]] [[Category:FreeBSD Terminology]]