init process in 2.2.19

init process in 2.2.19

[Subba Rao]

Hi,

I am trying to add a process which is to be managed by init. I have added the
following entry to /etc/inittab

SV:2345:respawn:env - PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin svscan /service </dev/null 2> dev/console

After saving, I execute the following command:

	# kill -HUP 1

This does not start the process I have added. The process that I have added
only starts when I do:

	# init u
or
	# telinit u

PS - The process will not start even after a reboot. I have to manually do one
of the above commands as root.

My kernel version is : 2.2.19
Distro : Slackware
GCC : gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)

Any help appreciated.

-- 

Subba Rao
subba9@home.com
http://members.home.net/subba9/

GPG public key ID 27FC9217

Re: init process in 2.2.19

[Jesse Pollard]

Subba Rao <subba9@home.com>:
> I am trying to add a process which is to be managed by init. I have added the
> following entry to /etc/inittab
> 
> SV:2345:respawn:env - PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin svscan /service </dev/null 2> dev/console
> 
> After saving, I execute the following command:
> 
> 	# kill -HUP 1
> 
> This does not start the process I have added. The process that I have added
> only starts when I do:
> 
> 	# init u
> or
> 	# telinit u
> 
> PS - The process will not start even after a reboot. I have to manually do one
> of the above commands as root.
> 
> My kernel version is : 2.2.19
> Distro : Slackware
> GCC : gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
> 
> Any help appreciated.

I'm using Slackware 7.1, so one of the following possible solutions may work:

First
	Make sure the daemon is available at boot time - if /usr/local/bin is
	where the svscan daemon exists, then /usr/local must be part of the
	root file system.

	What I do is have a "/host" directory tree on the root file system
	for this purpose. Alternatively, I start the daemon when the system
	enters multi-user mode (either /etc/rc.d/rc.local, or one of the
	already existing scripts related to what the daemon does).

A second possibility (try this first - its easer:
	I see that the daemon is to run in modes "2345". There is a possiblity
	that you have this entry near the beginning of the inittab. If so, try
	putting it at the end. I believe that init runs each line of the
	inittab for a given run level in the same order that it appears in the
	file. Putting the entry last should allow it to be started AFTER
	all file systems are mounted - the  entry for multiuser mode is:

	# Script to run when going multi user.
	rc:2345:wait:/etc/rc.d/rc.M

	If your daemon entry follows this line then it may work as you
	expect.

	Remember, any facility that the daemon depends on must be
	initialized before the daemon starts - If it uses the network
	then the network needs to be loaded (mine needs sockets loaded...)
	before the daemon is started.

	Note: since the assumption that the daemon is in /usr/local and
	      that /usr/local is a separate file system is true, then
	      you will no longer be able to dismount the /usr/local
	      file system while in multi-user mode (it's busy). This may
	      only be relevent to how your backups are done.

BTW, SIGHUP may not be the correct signal - from the init manpage:

       SIGHUP
            Init looks for /etc/initrunlvl and  /var/log/initrun-
            lvl.   If  one  of  these  files exist and contain an
            ASCII runlevel, init switches to  the  new  runlevel.
            This  is  for backwards compatibility only! .  In the
            normal case (the files don't exist) init behaves like
            telinit q was executed.

The only documented startup is "init u" or "telinit u". To re-read the
inittab file use "init q" or "telinit q". I suspect the manpage is a
little "inaccurate" in stating that SIGHUP is equivalent to "telinit q"

-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pollard@navo.hpc.mil

Any opinions expressed are solely my own.

Re: init process in 2.2.19

[Russell King]

On Thu, Apr 26, 2001 at 05:30:16PM +0000, Subba Rao wrote:
> I am trying to add a process which is to be managed by init. I have added the
> following entry to /etc/inittab
> 
> SV:2345:respawn:env - PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin svscan /service </dev/null 2> dev/console
> 
> After saving, I execute the following command:
> 
> 	# kill -HUP 1
> 
> This does not start the process I have added. The process that I have added
> only starts when I do:

telinit q tells init to re-read the inittab, as per the telinit man page.

--
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

Re: init process in 2.2.19

[Subba Rao]

On  0, Jesse Pollard <pollard@tomcat.admin.navo.hpc.mil> wrote:
> Subba Rao <subba9@home.com>:
> > I am trying to add a process which is to be managed by init. I have added the
> > following entry to /etc/inittab
> > 
> > SV:2345:respawn:env - PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin svscan /service </dev/null 2> dev/console
> > 
> > After saving, I execute the following command:
> > 
> > 	# kill -HUP 1
> > 
> > This does not start the process I have added. The process that I have added
> > only starts when I do:
> > 
> > 	# init u
> > or
> > 	# telinit u
> > 
> > PS - The process will not start even after a reboot. I have to manually do one
> > of the above commands as root.
> > 
> > My kernel version is : 2.2.19
> > Distro : Slackware
> > GCC : gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
> > 
> > Any help appreciated.
> 
> I'm using Slackware 7.1, so one of the following possible solutions may work:
> 

Forgot to mention that I am using Slackware 7.1 too

> A second possibility (try this first - its easer:
> 	I see that the daemon is to run in modes "2345". There is a possiblity
> 	that you have this entry near the beginning of the inittab. If so, try
> 	putting it at the end. I believe that init runs each line of the
> 	inittab for a given run level in the same order that it appears in the
> 	file. Putting the entry last should allow it to be started AFTER
> 	all file systems are mounted - the  entry for multiuser mode is:
> 
> 	# Script to run when going multi user.
> 	rc:2345:wait:/etc/rc.d/rc.M
>
>	<SNIP>
> 

Thank you for replying!

I have tried those methods and they did not work. What I did as recommended
by someone, is that I added "strace" to the process in /etc/inittab

SV:2345:respawn:strace env - PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin svscan /service </dev/null 2>/backup/strace.out

Instead of sending the strace messages to the console, I saved them to a file.
Part of the log is at the end of this note. Most of these messages seem to be
from the memory module.

If anyone could look at these messages and let me know how to fix it, I would
appreciate it.

Thank you in advance for any help!
-- 

Subba Rao
subba9@home.com
http://members.home.net/subba9/

GPG public key ID 27FC9217

----------------------------------------------------------------------------


execve("/usr/bin/env", ["env", "-", "PATH=/usr/local/bin:/usr/sbin:/usr/bin:/bin", "svscan", "/service"], [/* 16 vars */]) = 0
brk(0)                                  = 0x804a3c0
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=22195, ...}) = 0
old_mmap(NULL, 22195, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40014000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=1013224, ...}) = 0
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\250\206"..., 4096) = 4096
old_mmap(NULL, 954492, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x4001a000
mprotect(0x400fc000, 28796, PROT_NONE)  = 0
old_mmap(0x400fc000, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0xe1000) = 0x400fc000
old_mmap(0x40100000, 12412, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x40100000
close(3)                                = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40104000
mprotect(0x4001a000, 925696, PROT_READ|PROT_WRITE) = 0
mprotect(0x4001a000, 925696, PROT_READ|PROT_EXEC) = 0
munmap(0x40014000, 22195)               = 0
personality(PER_LINUX)                  = 0
getpid()                                = 880
brk(0)                                  = 0x804a3c0
brk(0x804a3f8)                          = 0x804a3f8
brk(0x804b000)                          = 0x804b000
execve("/usr/local/bin/svscan", ["svscan", "/service"], [/* 1 var */]) = 0
brk(0)                                  = 0x8053d20
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=22195, ...}) = 0
old_mmap(NULL, 22195, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40014000
close(3)                                = 0
open("/lib/libc.so.6", O_RDONLY)        = 3
fstat(3, {st_mode=S_IFREG|0755, st_size=1013224, ...}) = 0
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\250\206"..., 4096) = 4096
old_mmap(NULL, 954492, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x4001a000
mprotect(0x400fc000, 28796, PROT_NONE)  = 0
old_mmap(0x400fc000, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3, 0xe1000) = 0x400fc000
old_mmap(0x40100000, 12412, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x40100000
close(3)                                = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40104000
mprotect(0x4001a000, 925696, PROT_READ|PROT_WRITE) = 0
mprotect(0x4001a000, 925696, PROT_READ|PROT_EXEC) = 0
munmap(0x40014000, 22195)               = 0
personality(PER_LINUX)                  = 0
getpid()                                = 880
chdir("/service")                       = 0
wait4(-1, 0xbffffea8, WNOHANG, NULL)    = -1 ECHILD (No child processes)
open("/dev/null", O_RDONLY|O_NONBLOCK|0x10000) = -1 ENOTDIR (Not a directory)
open(".", O_RDONLY|O_NONBLOCK|0x10000)  = 3
fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
brk(0)                                  = 0x8053d20
brk(0x8054d68)                          = 0x8054d68
brk(0x8055000)                          = 0x8055000
getdents(3, /* 2 entries */, 3933)      = 28
getdents(3, /* 0 entries */, 3933)      = 0
close(3)                                = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({5, 0}, {5, 0})               = 0
wait4(-1, 0xbffffea8, WNOHANG, NULL)    = -1 ECHILD (No child processes)
open(".", O_RDONLY|O_NONBLOCK|0x10000)  = 3
fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
getdents(3, /* 2 entries */, 3933)      = 28
getdents(3, /* 0 entries */, 3933)      = 0
close(3)                                = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({5, 0}, {5, 0})               = 0
wait4(-1, 0xbffffea8, WNOHANG, NULL)    = -1 ECHILD (No child processes)
open(".", O_RDONLY|O_NONBLOCK|0x10000)  = 3
fstat(3, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(3, F_SETFD, FD_CLOEXEC)           = 0
getdents(3, /* 2 entries */, 3933)      = 28
getdents(3, /* 0 entries */, 3933)      = 0
close(3)                                = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({5, 0}, {5, 0})               = 0