WEBMIN- Managing Unix Systems Graphically

What is Webmin?

Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more.

Demo:

http://webmin-demo.virtualmin.com/   login: demo &  password: demo.

Download Link:

http://www.webmin.com/download.html 

How to Install:

Install on RedHat/CentOS/Fedora:

If you are using the RPM version of Webmin, first download the file from the downloads page , or run the command :

[root@UMLinux1 ~]# wget http://prdownloads.sourceforge.net/webadmin/webmin-1.710-1.noarch.rpm

and then run the command

[root@UMLinux1 ~]# rpm -U webmin-1.710-1.noarch.rpm

The rest of the install will be done automatically to the directory /usr/libexec/webmin, the administration username set to root and the password to your current root password. You should now be able to login to Webmin at the URL http://localhost:10000/.Or if accessing it remotely, replace localhost with your system's IP address.

If you want to connect from a remote server and your system has a firewall installed, see this page for instructions on how to open up port 10000.

Install on Debian:

If you are using the DEB version of webmin, first download the file from the downloads page , or run the command :

[root@UMLinux1 ~]# wget http://prdownloads.sourceforge.net/webadmin/webmin_1.710_all.deb

then run the command :

[root@UMLinux1 ~]# dpkg --install webmin_1.710_all.deb

The install will be done automatically to /usr/share/webmin, the administration username set to root and the password to your current root password. You should now be able to login to Webmin at the URL http://localhost:10000/. Or if accessing it remotely, replace localhost with your system's IP address.

How to Stop& Start Webmin Services:

In order to start the Webmin service on CentOS (Linux) you will need to issue the following command:

[root@UMLinux1 ~]# service webmin start

You can check to make sure that Webmin is running by issuing the following command:

[root@UMLinux1 ~]# service webmin status
Webmin (pid 1729) is running
[root@UMLinux1 ~]#

If you wish to configure your server to ensure that the Webmin service is started at boot time you can issue the following command:

[root@UMLinux1 ~]# chkconfig --level 3 webmin on

To verify that Webmin will start at boot, issue the following command:

[root@UMLinux1 ~]# chkconfig --list webmin
webmin 0:off 1:off 2:off 3:on 4:off 5:off 6:off
[root@UMLinux1 ~]#

In the previous listing, Webmin is listed to start in run level 3, which is the default run level that the dedicated servers boot into.

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Run VIO commands from the HMC using "viosvrcmd" without VIOs Passwords

Recently  we got a situation where  in we don't know the passwords of  either padmin/root of VIOS  but need to run commands in VIOs.

Found an interesting command  in HMC  called "viosvrcmd",which will enble us to run commands on VIOs through HMC.

viosvrcmd -m managed-system {-p partition-name | --id partition-ID} -c "command" [--help]

Description: viosvrcmd issues an I/O server command line interface (ioscli) command to a virtual I/O server partition.

The ioscli commands are passed from the Hardware Management Console (HMC) to the virtual I/O server partition over an RMC session.

RMC does not allow interactive execution of ioscli commands.

-m    VIOs managed system name

-p    VIOs hostname

--id  The partion ID of the VIOs

Note:You must either use this option to specify the ID of the partition, or use the  -p option to specify the partition's name. The --id and the -p options are mutually exclusive.

-c    The I/O server command line interface (ioscli) command to issue to the virtual I/O      server partition.

Note: Command must be enclosed in double quotes. Also, command cannot contain the      semicolon (;), greater than (>), or vertical bar (|) characters.

--help  Display the help text for this command and exit.

Here is an example:

hscroot@umhmc:~> viosvrcmd -m umfrm570 -p umvio1 -c "ioslevel"
2.2.0.0

Since  we can't give the ; or > or |  in the command , if you need to process the output using filters , you can use that after "".

hscroot@umhmc:~> viosvrcmd -m umfrm570 -p umvio1 -c "lsdev -virtual" | grep vfchost0
vfchost0         Available   Virtual FC Server Adapter

What if  you want to run  command as root (oem_setup_env) ,  

got a method from internet

hscroot@umhmc:~> viosvrcmd -m umfrm570 -p umvio1 -c "oem_setup_env
> whoami"
root

You can  run in one shot like below

hscroot@umhmc:~> viosvrcmd -m umfrm570 -p umvio1 -c "oem_setup_env\n whoami"
root

If you need to run multiple commands , you can use them by assiging the commands to a variable and call the variable in place of the command parameter.

hscroot@umhmc:~>command=`printf  "oem_setup_env\nchsec -f /etc/security/lastlog -a unsuccessful_login_count=0 -s padmin"`

hscroot@umhmc:~>viosvrcmd -m umfrm570 -p umvio1 -c "$command"

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Expressions used with if condition in shell scripts

1-1. Primary Expressions

Primary	Meaning
[ -a FILE ]	True if FILE exists.
[ -b FILE ]	True if FILE exists and is a block-special file.
[ -c FILE ]	True if FILE exists and is a character-special file.
[ -d FILE ]	True if FILE exists and is a directory.
[ -e FILE ]	True if FILE exists.
[ -f FILE ]	True if FILE exists and is a regular file.
[ -g FILE ]	True if FILE exists and its SGID bit is set.
[ -h FILE ]	True if FILE exists and is a symbolic link.
[ -k FILE ]	True if FILE exists and its sticky bit is set.
[ -p FILE ]	True if FILE exists and is a named pipe (FIFO).
[ -r FILE ]	True if FILE exists and is readable.
[ -s FILE ]	True if FILE exists and has a size greater than zero.
[ -t FD ]	True if file descriptor FD is open and refers to a terminal.
[ -u FILE ]	True if FILE exists and its SUID (set user ID) bit is set.
[ -w FILE ]	True if FILE exists and is writable.
[ -x FILE ]	True if FILE exists and is executable.
[ -O FILE ]	True if FILE exists and is owned by the effective user ID.
[ -G FILE ]	True if FILE exists and is owned by the effective group ID.
[ -L FILE ]	True if FILE exists and is a symbolic link.
[ -N FILE ]	True if FILE exists and has been modified since it was last read.
[ -S FILE ]	True if FILE exists and is a socket.
[ FILE1 -nt FILE2 ]	True if FILE1 has been changed more recently than FILE2, or if FILE1 exists and FILE2 does not.
[ FILE1 -ot FILE2 ]	True if FILE1 is older than FILE2, or is FILE2 exists and FILE1 does not.
[ FILE1 -ef FILE2 ]	True if FILE1 and FILE2 refer to the same device and inode numbers.
[ -o OPTIONNAME ]	True if shell option "OPTIONNAME" is enabled.
[ -z STRING ]	True of the length if "STRING" is zero.
[ -n STRING ] or [ STRING ]	True if the length of "STRING" is non-zero.
[ STRING1 == STRING2 ]	True if the strings are equal. "=" may be used instead of "==" for strict POSIX compliance.
[ STRING1 != STRING2 ]	True if the strings are not equal.
[ STRING1 < STRING2 ]	True if "STRING1" sorts before "STRING2" lexicographically in the current locale.
[ STRING1 > STRING2 ]	True if "STRING1" sorts after "STRING2" lexicographically in the current locale.
[ ARG1 OP ARG2 ]	"OP" is one of -eq, -ne, -lt, -le, -gt or -ge. These arithmetic binary operators return true if "ARG1" is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to "ARG2", respectively. "ARG1" and "ARG2" are integers.

Expressions may be combined using the following operators, listed in decreasing order of precedence:

1-2. Combining expressions

Operation	Effect
[ ! EXPR ]	True if EXPR is false.
[ ( EXPR ) ]	Returns the value of EXPR. This may be used to override the normal precedence of operators.
[ EXPR1 -a EXPR2 ]	True if both EXPR1 and EXPR2 are true.
[ EXPR1 -o EXPR2 ]	True if either EXPR1 or EXPR2 is true.

The [ (or test) built-in evaluates conditional expressions using a set of rules based on the number of arguments. Just like the if is closed with fi, the opening square bracket should be closed after the conditions have been listed.

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