Here is an error message logged in /var/log/user.log and found on a linux box running Ubuntu 9.10

auditd: /sbin/audispd permissions should be 0750

Auditd is a daemon which belongs to the auditd package. This package contains a bunch of user utilities to store and analyze all what it is being logged by the audit subsystem in the Linux 2.6 kernel.

The only thing to do for this release version of Ubuntu :

root@localhost:~# ls -l /sbin/audispd
-rwxr-xr-x 1 root root 96020 2009-09-10 00:52 /sbin/audispd

root@veronique-desktop:~# ls -l /sbin/audispd
-rwxr-x— 1 root root 96020 2009-09-10 00:52 /sbin/audispd

root@veronique-desktop:~# dpkg-reconfigure auditd
update-rc.d: warning: auditd start runlevel arguments (S) do not match LSB Default-Start values (2 3 4 5)
update-rc.d: warning: auditd stop runlevel arguments (0 6) do not match LSB Default-Stop values (0 1 6)

While using mondorescue to perform a full backup of a server running RHEL 5, here is a list of error messages found in /var/log/mondoarchive.log :

File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3006: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3049: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3109: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3129: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3196: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3268: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3326: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3385: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3450: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3512: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3574: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3631: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3687: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3749: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3805: /bin/bash
File descriptor 3 (/tmp/mojo-jojo.blah.qN83BE) leaked on lvm invocation. Parent PID 3861: /bin/bash

After googling a little bit, here is the first explanation I managed to find. It seems that the lvm utility inherited all the opened file descriptors from the shell where it was launched.

By default, only three file descriptors are opened : 0 standard input,  1 standard output and 2 error output. So, a file descriptor named 3 was opened by a program but not closed properly.

A similar bug was reported within the official Debian bugreport :

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=466138

Such as lspci, lshw, discover is a hardware identification system based on the libdiscover2 library.
The available version for Debian lenny is the following one : 2.1.2-3

To install it :

root@localhost:~# apt-get install discover

It will install the following extra packages : discover-data libdiscover2

To use it, run the command /sbin/discover as root or with an user having sufficient privileges.
To get a summary of the devices found on the different buses :

root@localhost:~# discover -b

To make a search by device type :

root@localhost:~# discover -t network
Realtek Semiconductor Co., Ltd. RTL-8110SC/8169SC Gigabit Ethernet

More information : man discover
http://packages.debian.org/lenny/discover

If you want to perform  redirection of a command run by sudo, you will get the following error :

The file access permissions do not allow the specified action 0403-005 Cannot create the specified file

What does it mean?

Redirection is some kind of built-in features of your current running shell. (bash or ksh). When you issue a command with sudo, the built-in fonctions can not work within the child process.  To overcome this issue, the only workaround is to launch your command within a subshell :

sudo sh -c ‘your command > file.out’