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如果你的inittab有问题了.恢复可以说比较麻烦, 如果在trouble shooting
中遇到, 那就真的很麻烦了. 以下提供一个最好的方法给那些不愿动太多脑的人,在三分钟内用最简单的方法不用记忆任何内容就可以自制一个inittab.
只要按照以下方法: 1 updatedb
2 locate inittab
看到这里也许你会以为我要用inittab的man page, 那没什么新鲜的一点不错, 但我不是要你看, 而是执行man inittab > a 把inittab的说明文档输出到a文件中
然后.....呵呵. 用vi编辑你会看到文件有许多的乱码.(在linux中会是乱码)
如下:
INITTAB(5) Linux System Administrator's Manual INITTAB(5)
N NA AM ME E
inittab - format of the inittab file used by the sysv-compatible init
process
D DE ES SC CR RI IP PT TI IO ON N
The i in ni it tt ta ab b file describes which processes are started at bootup and
during normal operation (e.g. /etc/init.d/boot, /etc/init.d/rc, get-
tys...). I In ni it t(8) distinguishes multiple _ r_ u_ n_ l_ e_ v_ e_ l_ s, each of which can
have its own set of processes that are started. Valid runlevels are
0 0-6 6 plus A A, B B, and C C for o on nd de em ma an nd d entries. An entry in the i in ni it tt ta ab b
file has the following format:
_ i_ d:_ r_ u_ n_ l_ e_ v_ e_ l_ s:_ a_ c_ t_ i_ o_ n:_ p_ r_ o_ c_ e_ s_ s
Lines beginning with `#' are ignored.
_ i_ d is a unique sequence of 1-4 characters which identifies an entry
in i in ni it tt ta ab b (for versions of sysvinit compiled with the _ o_ l_ d libc5
(< 5.2.18) or a.out libraries the limit is 2 characters).
Note: traditionally, for getty and other login processes, the
value of the _ i_ d field is kept the same as the suffix of the cor-
responding tty, e.g. 1 1 for t tt ty y1 1. Some ancient login accounting
programs might expect this, though I can't think of any.
_ r_ u_ n_ l_ e_ v_ e_ l_ s
lists the runlevels for which the specified action should be
taken.
_ a_ c_ t_ i_ o_ n describes which action should be taken.
_ p_ r_ o_ c_ e_ s_ s
specifies the process to be executed. If the process field
starts with a `+' character, i in ni it t will not do utmp and wtmp
accounting for that process. This is needed for gettys that
insist on doing their own utmp/wtmp housekeeping. This is also
a historic bug.
The _ r_ u_ n_ l_ e_ v_ e_ l_ s field may contain multiple characters for different run-
levels. For example, 1 12 23 3 specifies that the process should be started
in runlevels 1, 2, and 3. The _ r_ u_ n_ l_ e_ v_ e_ l_ s for o on nd de em ma an nd d entries may con-
tain an A A, B B, or C C. The _ r_ u_ n_ l_ e_ v_ e_ l_ s field of s sy ys si in ni it t, b bo oo ot t, and b bo oo ot tw wa ai it t
entries are ignored.
When the system runlevel is changed, any running processes that are not
specified for the new runlevel are killed, first with SIGTERM, then
with SIGKILL.
Valid actions for the _ a_ c_ t_ i_ o_ n field are:
r re es sp pa aw wn n
The process will be restarted whenever it terminates (e.g.
getty).
w wa ai it t The process will be started once when the specified runlevel is
entered and i in ni it t will wait for its termination.
o on nc ce e The process will be executed once when the specified runlevel is
entered.
b bo oo ot t The process will be executed during system boot. The _ r_ u_ n_ l_ e_ v_ e_ l_ s
field is ignored.
b bo oo ot tw wa ai it t
The process will be executed during system boot, while i in ni it t
waits for its termination (e.g. /etc/rc). The _ r_ u_ n_ l_ e_ v_ e_ l_ s field
is ignored.
o of ff f This does nothing.
o on nd de em ma an nd d
A process marked with an o on nd de em ma an nd d runlevel will be executed
whenever the specified o on nd de em ma an nd d runlevel is called. However, no
runlevel change will occur (o on nd de em ma an nd d runlevels are `a', `b', and
`c').
i in ni it td de ef fa au ul lt t
An i in ni it td de ef fa au ul lt t entry specifies the runlevel which should be
entered after system boot. If none exists, i in ni it t will ask for a
runlevel on the console. The _ p_ r_ o_ c_ e_ s_ s field is ignored.
s sy ys si in ni it t
The process will be executed during system boot. It will be exe-
cuted before any b bo oo ot t or b bo oo ot tw wa ai it t entries. The _ r_ u_ n_ l_ e_ v_ e_ l_ s field
is ignored.
p po ow we er rw wa ai it t
The process will be executed when the power goes down. Init is
usually informed about this by a process talking to a UPS con-
nected to the computer. I In ni it t will wait for the process to fin-
ish before continuing.
p po ow we er rf fa ai il l
As for p po ow we er rw wa ai it t, except that i in ni it t does not wait for the pro-
cess's completion.
p po ow we er ro ok kw wa ai it t
This process will be executed as soon as i in ni it t is informormed
that the power has been restored.
p po ow we er rf fa ai il ln no ow w
This process will be executed when i in ni it t is told that the battery
of the external UPS is almost empty and the power is failing
(provided that the external UPS and the monitoring process are
able to detect this condition).
c ct tr rl la al lt td de el l
The process will be executed when i in ni it t receives the SIGINT sig-
nal. This means that someone on the system console has pressed
the C CT TR RL L- -A AL LT T- -D DE EL L key combination. Typically one wants to execute
some sort of s sh hu ut td do ow wn n either to get into single-user level or to
reboot the machine.
k kb br re eq qu ue es st t
The process will be executed when i in ni it t receives a signal from
the keyboard handler that a special key combination was pressed
on the console keyboard.
The documentation for this function is not complete yet; more
documentation can be found in the kbd-x.xx packages (most recent
was kbd-0.94 at the time of this writing). Basically you want to
map some keyboard combination to the "KeyboardSignal" action.
For example, to map Alt-Uparrow for this purpose use the follow-
ing in your keymaps file:
alt keycode 103 = KeyboardSignal
E EX XA AM MP PL LE ES S
This is an example of a inittab which resembles the old Linux inittab:
这里这里 # inittab for linux
id:1:initdefault:
rc::bootwait:/etc/rc
1:1:respawn:/etc/getty 9600 tty1
2:1:respawn:/etc/getty 9600 tty2
3:1:respawn:/etc/getty 9600 tty3
4:1:respawn:/etc/getty 9600 tty4
This inittab file executes / /e et tc c/ /r rc c during boot and starts gettys on
tty1-tty4.
A more elaborate i in ni it tt ta ab b with different runlevels (see the comments
inside):
# Level to run in
id:2:initdefault:
# Boot-time system configuration/initialization script.
si::sysinit:/etc/init.d/rcS
# What to do in single-user mode.
~:S:wait:/sbin/sulogin
# /etc/init.d executes the S and K scripts upon change
# of runlevel.
#
# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.
l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
# What to do at the "3 finger salute".
ca::ctrlaltdel:/sbin/shutdown -t1 -h now
# Runlevel 2,3: getty on virtual consoles
# Runlevel 3: getty on terminal (ttyS0) and modem (ttyS1)
1:23:respawn:/sbin/getty tty1 VC linux
2:23:respawn:/sbin/getty tty2 VC linux
3:23:respawn:/sbin/getty tty3 VC linux
4:23:respawn:/sbin/getty tty4 VC linux
S0:3:respawn:/sbin/getty -L 9600 ttyS0 vt320
S1:3:respawn:/sbin/mgetty -x0 -D ttyS1
F FI IL LE ES S
/etc/inittab
A AU UT TH HO OR R
I In ni it t was written by Miquel van Smoorenburg (miquels@cistron.nl). This
manual page was written by Sebastian Lederer (lederer@francium.infor-
matik.uni-bonn.de) and modified by Michael Haardt (u31b3hs@pool.infor-
matik.rwth-aachen.de).
S SE EE E A AL LS SO O
i in ni it t(8), t te el li in ni it t(8)
Dec 4, 2001 INITTAB(5)
但这些只是格式不符的一些说明信息, 并没有用处. 你可以用一串的dd删除那些乱码,当你删到:
# inittab for linux (在上边有标记"这里这里")
id:1:initdefault:
rc::bootwait:/etc/rc
1:1:respawn:/etc/getty 9600 tty1
2:1:respawn:/etc/getty 9600 tty2
3:1:respawn:/etc/getty 9600 tty3
4:1:respawn:/etc/getty 9600 tty4
这时你就要停了. 看起来是不是非常熟悉?
对比一下, 这就是你的inittab中开始起作用的第一行.
做如下步骤 : 改id:1:initdefault: 为id:3:initdefault:
从id:1:initdefault: 再往下删. 不要以为
rc::bootwait:/etc/rc
1:1:respawn:/etc/getty 9600 tty1
2:1:respawn:/etc/getty 9600 tty2
3:1:respawn:/etc/getty 9600 tty3
4:1:respawn:/etc/getty 9600 tty4
是有用的. 删到.si::sysinit:/etc/init.d/rcS 将rcS改成rc.sysinit
再删到 l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6
要保留哦# What to do at the "3 finger salute".
要保留哦 ca::ctrlaltdel:/sbin/shutdown -t1 -h now
执行 1,$s/init.d/rc.d/g 接着删到
1:23:respawn:/sbin/getty tty1 VC linux
2:23:respawn:/sbin/getty tty2 VC linux
3:23:respawn:/sbin/getty tty3 VC linux
4:23:respawn:/sbin/getty tty4 VC linux
S0:3:respawn:/sbin/getty -L 9600 ttyS0 vt320
S1:3:respawn:/sbin/mgetty -x0 -D ttyS1
执行 1,$s/getty/mingetty/g 然后将tty1后的都删除将23改成23456, 不明白看下边: 1:23456:respawn:/sbin/mingetty tty1 VC linux
2:23456:respawn:/sbin/mingetty tty2
3:23456:respawn:/sbin/mingetty tty3
4:23456:respawn:/sbin/mingetty tty4
5:23456:respawn:/sbin/mingetty tty5
6:23456:respawn:/sbin/mingetty tty6
存盘改文件名为inittab重启试试? 你是不是可以将机器启动了? 其实inittab是非常重要的文件, 如果你能背下来是最好的. 做为管理员你也应该有这种水平,但对一些记忆并不好的人或在考试时紧张的人来说. 这无疑是你的救命草. 当然,你在rescue可能不能做updatedb 但你可以man或将inittab的5.gz的位置记下.就是 /usr/share/man/man5/inittab.5.gz稍微懂一些的人都会知道share目录是放说明文档的地方吧? 如果你不想耽误考试中很紧的时间的话, 这就是你最好的解决方法. 但最后要说明的是, 这个文件并没有说inittab中的三个重启动的命令, 但这并不影响inittab的使用. 以上是经过测试的. 一定能用.希望对你有帮助. |
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狗仔卡
发表于 2004-11-21 20:52:43
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发表于 2004-11-22 09:29:14