System Administration Original
In this module, students will install debian to a virtual machine under vmware. Through out the course, these virtual machines will be primary development platform for the students. They will be responsible for maintaining them. Advanced topics to be discussed in the class: NFS, LDAP, Network Booting
Contents
Linux Kernel
What seperates Linux from other Unix variants is its kernel. The kernel is the most important component of the operating system. It is responsible for scheduling task, providing access to the hardware devices, allocating memory to the programs etc... Linux Kernel
The linux kernel provides both monolithic and modular approach. A monolithic kernel is a single program that contains all the code so any addition to kernel (such as code to access a driver) requires recompiling the code. A monolithic kernel is usually a little faster and could have a smaller size since the absolutely necessary code is there. The modular kernel, on the other hand, enables dynamic loading and unloading of kernel code. Typical modules include the device drivers. Thanks to this modular approach, Linux seldom requires reboot after installing a new device.
User Interaction in Linux
Bash
Bash is one of the shells installed by default (and it is default in most systems). It is located at /bin/ directory. Bash is a derivative of sh one of the first shells. As a more powerful descendant of bash, ksh was not available freely at the time, bash was developed to replace ksh.
Variables
It is possible to use variable in bash. When setting a variable, that variable is written by its name (no pre-decleration required). However, to use it you need to put special character $ in front of the variable. For example,
MYVARIABLE="this is a test"
sets the value of MYVARIABLE whereas
echo $MYVARIABLE
shows the value of myvariable. If you want your variable to be accessible to the child processes, you need to export it with
export $MYVARIABLE
after you set it. Alternatively, you can set and export it at the same time.
export MYVARIABLE="this is a test"
You can see the available variables by typing
set
Some of interesting variables are:
PATH: search path for the commands
PWD: name of the current directory
SHELL:type of shell
TERM: type of the terminal
USER: the account name
HOME: the user's home directory
PS1: the prompt at command line
$$: the process id of current shell
$RANDOM: a random value
$?: the return value of the last command
$_: the last argument of the previous command
$#: where # is a number, the value of the #th argument
IFS: input field separator
Running Programs
In linux, it is enough to type the name of a program to execute it. The name could be absolute (i.e., full name including the directories, such as /mydir/myprogram), or relative (the location with respect to current directory, such as ../../mydir/myprogram). In order to avoid typing the directory names every time you want to run a program, a list of directories can be specified by default in $PATH variable. If you type a command, the directories in that variable are going to be added to your program in the order of their occurrence. The first program found is then going to be executed.
A program runs in the foreground (unless it detaches itself from the terminal) by default. You can run a program in the background by adding & at of the command (after arguments). In this case, the shell would fork a process for that program and enable the command prompt back for input. At any time, jobs command can be used to see the processes running at the background. fg command brings the specified process back to foreground. A program running in the background can be stopped by typing ctrl-c in most cases. Typing ctrl-z interrupts a program running in the foreground. If a program is interrupted, it will not continue executing until it is resumed. An interrupted program can be brought back to foreground by fg, or it could be send to background by bg.
A process can be killed by kill command.
kill process-number
in some cases, kill signal can be ignored, so it may be necessary to force by sending an absolute KILL signal.
kill -9 process-number
The running processes can be found by typing ps(see the processes in the current shell), or ps -ef(see all processes).
A program's standard output can be send to a file by typing >filename at the end. Similarly, >> appends to a file. In linux, there are three default file handlers, standard input or STDIN, standard output, or STDOUT and standard error or STDERR. STDOUT has a file handler number 1 and STDERR has a number of 2. In bash, you can direct either of these handlers to a file. For example
someprogram 1>filename
redirects the standard output, where as
someprogram 2>filename
redirects the error output. Alternatively, you can redirect one file handler to another, such as
someprogram 2>&1
where STDERR is redirected to STDOUT.
Similarly, output of program can be redirected to the input of another program through pipes, e.g.,
program1 | program2
where program1's output is send as an input to program2.
Redirection is possible for STDIN too. A program can get its input by redirecting STDIN using <
myprogram < inputfile
Finally, ` can be used to capture the output of a program, and use it as a string such as in setting a variable
MYVARIABLE=`someprogram` echo $MYVARIABLE
Programming the shell
As bash is nothing but interpreter, it actually comes with a built-in programming language. Users can take the advantage of this powerful language to have a more flexible communication with the system. The programs can be directly typed at the command line or they can be read from the text files (scripts). For example,
bash commandfile
reads and executes the commands from the text file named commandfile. A better approach is to make commandfile executable and run it as if its is a program
chmod a+x commandfile ./commandfile
In this case, the shell is going to execute commandfile. If you want to specify another shell as the interpreter of commandfile, you can specify the interpreter program in the first line starting with #!, e.g.
#!/bin/sh ls
would force bash to call sh program to run remaining of the commands. It is a good idea to always specify the interpreter at the first line of the scripts. For our purposes, it would be
#!/bin/bash
Statements
Any line in a bash script is a program to be executed.
Conditional statements
Bash supports if statements. The format is
if [ CONDITION ] then somecommand fi
or
if [ CONDITION ] then somecommand else someothercommand fi
CONDITION could be a logical statement or it could be a test (man test). For example
if [ $val = 5 ]
or
if [ $val -eq 5 ] echo value is 5 fi
if [ somefile1 -ot somefile2 ]; then echo somefile1 is older than somefile2 fi
Bash also has case statements. The format is
case $mywar in
value1)
commands;
;;
value2)
commands;
;;
*)
commands;
;;
esac
In this case, ;; means end of a case block and * means catch anything.
In general, it would be better to include a string variable within quotes, "'. There reason is, if you have for example,
myvar="A very good text was here. Now it is gone and left its place to this boring message" if [ $myvar = "This is a very good text" ]
would fail with an error message as $myvar would be expanded to its content
if [ A very good text was here. Now it is gone and left its place to this boring message = This is a very good text" ]
to avoid this, you should have the statement as
if [ "$myvar" = "This is a very good text" ]
Loop statements
Bash provides standard loop statements, for, while, until. They can be executed in a script or it could be typed at the command prompt.
The format of for statement is
for VAR in somevalue1 somevalue2 .... somevaluen do executesomecommand done
This loop will execute the for block for each value of VAR. For example,
sum=0 for i in 1 2 3 4 5 6 7 8 9 10 do sum=$[$sum+$i] done
would sum numbers from 1 to 10. We can also use other techniques in for line, e.g. replacing for in the above code with
for i in `seq 1 1000`
would get the sum from 1 to 1000. Note the usage of `
The format of while and until are very similar
while [ CONDITION ]
do
execute some command
done
and
until [ CONDITION ] do execute some command done
Both of these commands CONDITION similar to if statement.
Functions
Bash also provides functions. They could be defined at command prompt and then can be called from command prompt. The structure of a function is similar to modern languages.
myfunction(){
execute some commands
}
The function then can be called with
myfunction
You can send parameters with to the function by adding them next to the function name
myfunction arg1 arg2 ....
and within a function, you can access the arguments using $#, i.e., $1 for first argument, $2 for second argument etc...
Networking
In linux, you can see your network information by typing ifconfig.
. This command shows the status information of each network interface. The interface lo is special interface with IP address 127.0.0.1. This refers to your local machine. Any connection to your local machine goes through this pseudo-interface. Typicall network interfaces include eth0, eth1,..., wlan0 etc. The ethernet cards are represented with eth, whereas wireless cards are usually wlan. ifconfig also gives information such as hardware address (MAC), broadcast and network.
You can start or stop networking by calling /etc/init.d/networking script. As most of init.d scripts, this script takes several options, such as start, stop, restart. Note even if you stop networking, you would still have your lo interface. You can look the code of this script to find out what it actually does. You can also stop or start individual interfaces by using ifup and ifdown commands.
The network configuration files are stored at /etc/network. For example, /etc/network/interfaces contain the defaults for each interface. For example, you can specify the static ip, netmask, network, broadcast and default gateway for eth0. This default options for the interfaces can be overwritten by calling ifconfig command. /etc/network/if-down.d and /etc/network/if-up.d directories contain the scripts that are going to be executed when an interface is turned on or off.
Configuring Your System
Updating repositories and installing new software
The package management tool in Debian is dpkg, and the package format is deb. If you have a deb package, you can install the package by typing
dpkg -i somepackage.deb
This process requires for you to go and download deb file yourself (or create it), and also it requires you to install the dependencies too. An alternative is to use apt. apt searches online repositories and creates a list of available packages. The locations of the packages are specified at the file /etc/apt/sources.list (I think one of the closest mirrors is uchicago, however wuarchive may have debian mirrors too). You can install a package with
apt-get install package-name
if you don't know the exact name of your package, you can search the name by typing the command
apt-cache search keyword
The deb files apt would download for installation is placed the cache directory at /var/apt/cache
While apt-get provides you ability to install dependency files automatically, an alternative installer, aptitude provides better dependency resolving. aptitude works very similar to apt-get but they use different database files so utilizing both of them together may cause some small problems such as complaining missing dependencies while they were already installed.
Finally, as the online repositories are updated frequently, you may want to update your database by typing
apt-get update
Remote Access
You would probably like to have the remote access to your machine. A secure way of doing this using SSH(secure shell). Ssh access requires sshd daemon running in your machine. You can install ssh by running
apt-get install openssh-server
The configuration files for SSH are in /etc/ssh. You can modify some of them to satify your needs. For example, it is always a good idea to disable root access over ssh. This could be done by editing /etc/ssh/sshd_config and setting
PermitRootLogin no
It is also possible to use ssh to access your machine without specifying your password (very useful but dangerous option). This is done by generating a public/private encryption key pair on your local host, and copying the public key to the remote machine. The details can be found here [1]
Disabling Root User
As root is a very powerful account (and well-known), it is preferable to disable root account. In fact, some linux distributions now come with disabled root accounts. In order to disable root account, we need to have a way to access superuser privileges. sudo command provides this. If you haven't installed sudo, you can install it by typing apt-get install sudo. Sudo enables individual users to run some commands as root users. It has a configuration file /etc/sudoers where the access priviledges are specified. For example, a line such as
alice ALL=(ALL) ALL
gives permission to alice to run any command as root. The first time alice runs sudo, it will ask alice's password but for the consecutive sudoes, it won't, provided that there was a recent password verification. Hence, alice can use sudo to become root by typing
sudo bash
or
sudo su -
sudoers file can also be configured so that another user won't be asked for password and that user can only run specified commands such as
bruce ALL= NOPASSWD: /usr/sbin/kill,/usr/bin/killall
Bruce can run only kill, and killall programs as root.
In order to disable your root, you should first enable one user to have root priviledges. So make sure that there is at least one user with all permissions (such as alice above). You can use any editor, but usually there is commands such as visudo or sudoedit that locks the sudoers files to disable multiple writing.
Now, you want to disable root access. This could be done by either typing passwd -l root to lock the root account or editing /etc/shadow file and replacing root's encrypted password with *. From now on, no body can login to your system as root.
Setting System Time
If you want to avoid setting your systems time manually at every daylight savings change, you should better start using a Network Time Server. It is very easy. All you need to do is to install an NTP daemon. There are several ones, but the simplest one is ntp. Just install it using apt-get
apt-get install ntp
ntp daemon uses /etc/ntp.conf configuration file to find out the IP of time servers. Make sure that your servers make sense. Also, you can edit /etc/timezone to reflect your machine's timezone.
Partitioning Hard Disks
Please look at the video tutorial belov
Setting LDAP
LDAP means Lightweight Directory Access Protocol. It is commonly used for getting personal and authentication information from a central server. More information for LDAP is available at LDAP page.
Your initial LDAP database
Before you start installing LDAP, lets look at what kind of information we are going to use. You can write that information to a text file to populate your LDAP database later. The structure you decided is also important as you have to let the LDAP server knows about it.
Lets assume wer are creating an LDAP service the Babylon 5 space station, and decided you babylon5.ldif file as initial entries. At the top, we need to define an organization and then we need to describe the organizational units. Our organizational unit will be Interstallar Alliance (ISA) and our organizational units will be the planets belonging to this organization (Earth and Minbar for the sake of briefness). Then we will have information about people who are citizens of either planets.
We describe ISA with
dn: o=ISA objectclass: top objectClass: organization o: ISA description: Interstellar Alliance
It says, the organization name (o) is ISA, and this entry has a distinct name (dn) of o=ISA. It is also an instance of classes top and organization. Under this organization, we need to have entries for Earth and Minbar.
dn: ou=Earth,o=ISA ou: Earth objectClass: top objectClass: organizationalUnit description: Human
dn: ou=Minbar,o=ISA ou: Minbar objectClass: top objectClass: organizationalUnit description: Members of Minbar
Note that, dns for child nodes contain the path to reach them.
We also need an administrator for LDA so that we can access and modify the entries later.
dn: cn=isaadmin,o=ISA objectClass: organizationalRole cn: isaadmin description: LDAP directory administrator
Then we will have the information about people.
dn: cn=John Sheridan,ou=Earth,o=ISA ou: Earth o: ISA cn: John Sheridan objectClass: top objectClass: person
objectClass: organizationalPerson objectClass: inetOrgPerson givenname: John sn: Sheridan postalAddress: Human Sector l: Babylon 5 homeDirectory: /tmp st: Babylon 5 telephoneNumber: (800)555-1212 homePhone: 800-555-1313 facsimileTelephoneNumber: 800-555-1414 userPassword: sheridan title: Commander of Babylon 5
This entry is an instance of a class derived from person, organizationalPerson,inetOrgPerson, hence its attributes are from those classes. There are several optional attributes these classes contain but not included in the description of this person. If you want to use LDAP only to provide the information about the people, this description would be sufficient. But if you need to provide authantication to other systems, you need other information too. First of all, you need to inform LDAP that this entry also contain user information by adding object classes posixAccount and shadowAccount. Furthermore, you need the give other information such as account name, user id, the groups this person belongs to, the home directory etc.
So a more general entry for this person could be:
dn: cn=John Sheridan,ou=Earth,o=ISA ou: Earth o: ISA cn: John Sheridan objectClass: top objectClass: person objectClass: posixAccount objectClass: shadowAccount objectClass: organizationalPerson objectClass: inetOrgPerson givenname: John sn: Sheridan uid: starkiller postalAddress: Human Sector l: Babylon 5 uidNumber: 1025 gidNumber: 9000 homeDirectory: /tmp st: Babylon 5 telephoneNumber: (800)555-1212 homePhone: 800-555-1313 facsimileTelephoneNumber: 800-555-1414 userPassword: * title: Commander of Babylon 5
So Joh Sheridan has account name starkiller with UID 1025 and home directory /tmp. Notice that, we set this person's group number to 9000. But how does a client machine knows a group? Nicely, LDAP also serve information about groups, so you can create a group entry.
dn: cn=chargroup,o=ISA
objectClass: posixGroup
objectClass: top
cn: chargroup
userPassword: {crypt}x
gidNumber: 9000
Finally, you can repeat this for other personal.
Setting the server
In order to use LDAP, we need slapd, ldap-utils, libldap2, libldap2-dev packages.
apt-get install slapd ldap-utils libldap2 libldap2-dev
If the installation program asks for an admin password, type a password but don't worry about it much since we will create our own admin later.
slapd is an LDAP server. It has its configuration files under /etc/ldap. For now, we are interested in slapd.conf. This files include some default schema that describes object classes you can use in your entities. It also describes a default LDAP directory database.
database bdb
describes Berkley database is going to be used (you can select other alternatives). It also has default suffix. If you want, you modify the lines for default database description or you can setup your own database. Basically,you need to select a suffix for your database (usually the organization's dn) and give dn of the LDAP administrator and its password. Finally, you need to specify the permissions.
If we continue with Babylon 5 example, remember our organization had 'dn: o=ISA' so that will be our suffix
suffix "o=ISA"
We wshould also need to inform LDAP about the administrator account so that we can access LDAP and modify it.
rootdn "cn=isaadmin,o=ISA" rootpw jms_rulez
I left the password plain, but you can also use encrypted passwords. We need to give the administrator the full access to modify the database:
# The admin dn has full write access, everyone else
# can read everything.
access to *
by dn="cn=isaadmin,o=ISA" write
by * read
and the others can modify their password
access to attrs=userPassword,shadowLastChange
by dn="cn=isaadmin,o=ISA" write
by anonymous auth
by self write
by * none
Actually, the last bit needs to come before the administrator access since otherwise, it will overwrite the administrator's write access.
So we have ready to use ldap. Since we have updated slapd.conf, we need to restart slapd.
/etc/init.d/slapd restart
and we need to populate the initial database:
ldapadd -f ~/babylon5.ldif -xv -D "cn=isaadmin,o=ISA" -h 127.0.0.1 -w jms_rulez
The format is
ldapadd -f LDIF_FILE_TO_BE_USED -xv -D "admin's dn' -h HOSTNAME_FOR_LDAP_SERVER -wADMIN_PASSWORD
-x option tells to use plain authentication and -v says verbose.
If you have problems, you can stop slapd and use
slapadd -u -l babylon5.ldif -b o=ISA -cv
to see detailed error messages. slapadd accesses your database directory directly without going through the server. If you want to remove the LDAP directory, you can directly remove everything under /var/lib/ldap/ (the path specified in slapd.conf) and the next time you start slapd, it will create initial files (but you need to repopulate).
You can verify if your LDAP is working with
ldapsearch -x -b 'o=ISA'
ldapsearch takes other parameters to let you search for specific information. In our case, we just look all the entries that have o=ISA.
Setting the client
First you need to install the client side packages:
apt-get install ldap-utils libpam-ldap libnss-ldap nscd
Now we need to inform linux to look at ldap. We do that by modifying /etc/nsswitch.conf
passwd: ldap compat group: ldap compat shadow: ldap compat
PAM is the linux module that handles authentications. It may have different authantication for different programs. We need to update authentications methods so that you can use ldap. This is done by editing files:
/etc/pam.d/common-account
account sufficient pam_ldap.so account required pam_unix.so try_first_pass
/etc/pam.d/common-auth
auth sufficient pam_ldap.so auth required pam_unix.so nullok_secure try_first_pass
/etc/pam.d/common-password
password sufficient pam_ldap.so password required pam_unix.so nullok obscure min=4 max=8 md5 try_first_pass
We also need to update /etc/ldap/ldap.conf (with your partner's information)
BASE yourbase URI ldap://yourhost rootbinddn Your admin's dn
In our example case, it will be
BASE o=ISA URI ldap://128.252.160.XXX #replace XXX with the final IP number rootbinddn cn=isaadmin,o=ISA
and do similar changes to /etc/libnss-ldap.conf (with your partner's information)
base o=ISA host 128.252.160.xxx #replace xxx with your server's IP rootbinddn cn=isaadmin,o=ISA
Both libnss and pam_ldap get the rootbindn's password from text files so add your administrator's password there and make sure those file have 500 permissions. (with your partner's password)
/etc/libnss-ldap.secret and /etc/pam_ldap.secret
Finally you need to restart nscd
/etc/init.d/nscd restart
I heard nscd uses a local cache, that cache may not be updated after LDAP configuration, and it was suggested to install nscd after LDAP configured. An alternative is to disable the cache for passord file in ncsd configuration file /etc/nscd.conf
enable-cache passwd no
Now you can change the password of a user in LDAP with
password username
try you can do that with user starkiller and try to login your system as starkiller
You can get password file with
getent passwd
Your LDAP entries should be there
Alternatively, you can type
getent passwd nameofauser
If you don't see anything after these commands, something is missing in your configuration, make sure your admin password is right and URIs, bases are correct. Try your access to ldap server by using ldapsearch
ldapsearch -x -D 'cn=isaadmin,o=ISA' -w jms_rulez #make sure you have your parameters for -w (password) and -D (admin entity)
Additional Info
Init Process / PC Boot Procedure
Please refer to http://www.yolinux.com/TUTORIALS/LinuxTutorialInitProcess.html
crontab
crontab is the name of the file which is used to control the cron service, as well as a command which is used to edit this file and submit it to the crond daemon for execution.
The crontab command is most often invoked with the -e option, which launches your preferred editor as specified by the $VISUAL environment variable.
Alternatively, any text file can serve as a crontab file so long as it is properly formatted. To load that file into the computer to be executed by the crond daemon, simply execute the following command:
crontab /path/to/new/crontab/file.txt
You can list the contents of your current crontab by executing crontab -l at the command line.
Each line in the crontab file can be a comment, a variable declaration or an event line.
Comments
Comments begin with a comment mark #, and must be on a line by themselves.
Variable declarations
Variable declarations are of the form
- name=value
Unlike bash scripts, you can get away with putting spaces around the = sign. It's probably a bad habit to get into, though.
Event lines
Each event line specifies a time and a date, and a command which is to be executed them, in the format
- minute hour date month day command
The first five fields can be numbers or ranges, in the format described below. Note that you can specify either the date (i.e. within the month) or the day (of the week); the other field should be set to *.
The sixth field is a command with parameters. Percent signs -- unless escaped with a \ backslash -- will be turned into newlines, and everything after the first one of these will be fed into the command's standard input stream.
It is also possible to execute shell scripts or run various applications with cron. Let's imagine, you want to play music in the morning to awake you. If you want it to start at 6AM every weekday morning, here's the crontab line you need:
0 6 * * 1-5 /home/user/alarm.sh
Normally, the crontab file contains a MAILTO variable that directs output (stdout and stderr) to be mailed to the respective address (e.g. MAILTO=dave). If this is not working, the script may quit unexpectedly when its output has nowhere to go.
Range format
| * | Any number |
| */5 | Any number, in steps of 5 |
| 1-6 | Any number between 1 and 6 (inclusive) |
| 0-30/5 | Any number between 0 and 30, in steps of 5 |
| 1,4,9 | 1, 4 or 9 |
Months
Months can be specified in numbers or in words.
1 = jan
2 = feb
...
12 = dec
Days of the week
Days of the week also can be specified in numbers or words.
0 = Sunday
1 = Monday
2 = Tuesday
...
6 - Saturday
7 - Sunday
Examples
# fetch e-mail every ten minutes */10 * * * * fetchmail # send myself a birthday greeting 0 9 7 28 * mail -s'Happy Birthday' ajs318%Many Happy Returns - you old fart!%.%% # back up my recipe database every Monday 30 5 * * 1 mysqldump --opt recipes > /home/ajs318/backups/recipes.sql
Example bulk mailer
Recipients file
John Doe, johndoe@somedomain.com Jane Doe, janedoe@somedomain.com
Bash script mailer.sh
#!/bin/bash
#run as ./mailer.sh RECIPIENTS_FILE
export IFS=$'\t\n'
for i in `cat $1`
do
MAIL=`echo "$i"|awk 'BEGIN { FS = "," } ; { print $2 };' `
NAME=`echo "$i"|awk 'BEGIN { FS = "," } ; { print $1 };' `
echo NAME="$NAME" MAIL="$MAIL"
echo "Hello $NAME" >/tmp/mail-body
echo "This is a spam so please visit my website\nsincerely" >>/tmp/mail-body
mail -s"Greetings" $MAIL </tmp/mail-body
done
Important Items
Commands
ls List file(s)
cd Change directory
cp Copy file(s)
mv Move file(s)
rm Remove file(s)
ln Create a link to a file
mkdir Create a directory
rmdir Remove a directory
chown Change the owner of a file
chgrp Change the group of a file
chmod Change the security permissions of a file
cat Display the contents of a file
less Display the contents of a file, wait for the user at each page
grep Display the lines of a file or files matching user specified string
diff Display the difference between two files
df Display free diskspace
du Display disk usage
free Display memory usage information
date Display current time and date
top Display the CPU and Memory usages of current processes
ps Display current processes
kill Terminate a running process
killall Terminate the running process matching user specified criterias
ping Ping a host
host Get the IP address of a host
passwd Change the user password
su Switch to the privileges of another user
shutdown Power off the computer
reboot Reboot the computer
clear Clear the terminal
vi Visual Editor
ifconfig Display/Configure a network device
file Show the file type
lsmod Display loaded kernel modules
insmod Install a kernel module
modprobe Load a kernel module (also load the dependencies)
adduser Add a new user
exit Exit from a shell
lpr Print a file
head Display lines at the beginning of a file
tail Display lines at the end of a file
pwd Display the name of the current directory
lsof Open files in the system
netstat Statistics related to open sockets
Directories
/var Location of frequently changing system files
/etc Common configuration files
/root Root's home directory
/home The home directories for regular users
/usr System programs and documents
/proc System resources and consumptions
/tmp Temporary files
/lib Kernel libraries
/boot Boot files
Files
Under /etc
/etc/apt/apt.conf Configuration file for apt
/etc/apt/sources.list List of online repositories
/etc/crontab System-wide crontab file
/etc/fstab Information about default partitions to be mounted
/etc/group List of groups in the system
/etc/hosts List of IP addresses with their names
/etc/inittab What to do at each run-level
/etc/inetd.conf Configuration file for some internet services (replaced by xinetd.* in most systems)
/etc/modules.conf Module information for the boot
/etc/motd Message to be seen at the login prompt
/etc/passwd User information
/etc/profile System level initial file for sh and its derivatives
/etc/shadow User passwords
Under /var
/var/log/messages System/Kernel messages
/var/log/syslog System log (mostly for Daemons)
/var/log/wtmp' User access log (binary)
/var/log/dmesg Boot-up messages
/var/log/auth.log Authorization logs
Video Tutorials
Creating a new virtual machine with VMWare: Watch Download (requires Ogg codecs)
Adding a virtual hard disk with VMWare : Watch
Installing GNU/Debian Linux: Watch Download (requires Ogg codecs)
Upgrading Debian to Testing: Watch
Partitioning your disks and mounting them: Watch
SSH tunneling for vmware in windows: Watch
Suggested Readings
Linux System Administration Tutorial
Working with the Shell (SUSE Documentation)
Making the Transition to Linux: A Guide to the Linux Command Line Interface for Students
Teams for this module
This assignment can be done either individual or two-student teams. Feel free to select your team member.
zoo.cse.wustl.edu users:
Adam Michael Basloe
Andrew Nemec Bort
Michael Rene Browning
Gail Crystal Burks
Vanetia Nikole Cannon
Mark Evan Davis
Michael Frances Fahey
William Cannon Fargo
Paul Manfred Heider
oz.cse.wustl.edu users:
Andrew David Kanyer
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