System: /kernel: Operation not permitted
(last edit: 2001-06-13)
                   
Problem
You think you are superuser and you think you are god but you get something like the
following:

   $root@host:/#ls -l
   ...
   -r-xr-xr-x   1 root  wheel  1782122 Jun  1 20:29 kernel
   ...
   $root@host:/#chmod 777 kernel
   chmod: kernel: Operation not permitted
   $root@host:/#

Lets first take a closer look:

   $root@host:/#ls -lo
   ...  
   lrwxr-xr-x   1 root  wheel  -          9 Apr 10 16:46 home -> /usr/home
   -r-xr-xr-x   1 root  wheel  schg 1782122 Jun  1 20:29 kernel
   -r-xr-xr-x   1 root  wheel  -    3258128 Jun 13 20:25 kernel.GENERIC
   ...

From the 'ls' man page: "-o      Include the file flags in a long (-l) output."
So the 'schg' flag is set on that file. You can change this option with the 'chflags'
command.

man chflags
NAME
     chflags - change file flags

SYNOPSIS
     chflags [-R [-H | -L | -P]] flags file ...

DESCRIPTION
     The chflags utility modifies the file flags of the listed files as speci-
     fied by the flags operand.

...

     The flags are specified as an octal number or a comma separated list of
     keywords.  The following keywords are currently defined:

           arch    set the archived flag (super-user only)
           opaque  set the opaque flag (owner or super-user only)
           nodump  set the nodump flag (owner or super-user only)
           sappnd  set the system append-only flag (super-user only)
           schg    set the system immutable flag (super-user only)
           sunlnk  set the system undeletable flag (super-user only)
           uappnd  set the user append-only flag (owner or super-user only)
           uchg    set the user immutable flag (owner or super-user only)
           uunlnk  set the user undeletable flag (owner or super-user only)
           archived, sappend, schange, simmutable, uappend, uchange, uimmutable,
           sunlink, uunlink
                   aliases for the above

     Putting the letters ``no'' before an option causes the flag to be turned
     off.

So when you do the following:

   $root@host:/#chflags noschg kernel
   $root@host:/#ls -lo kernel
   -r-xr-xr-x  1 root  wheel  - 1782122 Jun  1 20:29 kernel
 
then you see that you are realy the true and only master of your machine.