Sunday, October 03, 2010

Run your DataCard on OpenSuse 11.3


Past many nights, I spend playing with scripts and USB configuration to connect my ZTE data-card on Linux and results were disappointing.... But the Good News is: I finally got it work and surprisingly without working on any script.
Well solution is very very simple and here it is........
run YaST
Authenticate as root

In Network Devices select Modem
In Modem Configuraion Overview click Add
In Modem Parameters choose your modem device e.g. /dev/ttyUSB0 (already detected). Click Next
In Select Internet Service Providers Choose New
In Provider Parameters fill The followings:
Provider Name e.g. Reliance
Phone No. e.g. #777
User Name 93XXXXXXXX and Password ********** and Click Next
In Connection Parameters select Automatic Dialing and Click Next
You will be back to Modem Configuraion Overview click OK.... its done
Run qinternet from Application Browser (it comes with SUSE. if you did not install it use YaST)
In side the lower panel a "plug" like icon will appear. Click it for connecting/disconnecting.

Friday, September 17, 2010

Protect GRUB with password

GRUB is very important since it is the first software program that runs when the computer starts
and we have to secure it as much as possible to avoid any possible problem. Below is a default GRUB configuration file and security I recommend you to apply. The text in bold are the parts of the configuration file that must be customized and adjusted to satisfy our needs.
Edit the grub.conf file (vi /boot/grub/grub.conf) and set your needs. Below is what we recommend you:
default=0
timeout=0

splashimage=(hd0,0)/grub/splash.xpm.gzpassword --md5 $1$oKr0ÝmFo$tPYwkkvQbtqo1erwHj5wb/
title Red Hat Linux (2.4.18-3)
root (hd0,0)
kernel /vmlinuz-2.4.18-3 ro root=/dev/sda5
initrd /initrd-2.4.18-3.img


password --md5 $1$bgGCL/$4yF3t0py.IjU0LU.q7YfB1

This option “password” is used to inform GRUB to ask for a password and disallows any
interactive control, until you press the key <p> and enter a correct password. The option --md5
tells GRUB that a password in MD5 format is required as a value. If it is omitted, GRUB assumes
the specified password is in clear text.
When we have installed the operating system, we have already configured GRUB with a
password protection. This password is what you see here. If you want to change it, you have to
use the “grub-md5-crypt” command to generate a new encrypt password it in MD5 format.
• This can be done with the following command:
[root@dev /]# grub-md5-crypt
Password:
$1$bgGCL/$4yF3t0py.IjU0LU.q7YfB184

Once the above command has been issued, you have to cut and paste the encrypted password
to your configuration file.

Monday, September 06, 2010

tar Magic

Tar is commonly used for packaging files on Linux. Tar uses many command-line options like following:

-f    To use a tarfile
-c   To create a new tarfile
-x   To extract files from a tarfile.

You also can compress the resulting tarfile via two methods. 
-j    To use bzip2
-z    To use gzip

You can tar up a directory and all of its subdirectories by using:
tar cf archive.tar dir

Then, extract it in another directory with:
tar xf archive.tar

When creating a tarfile, you can assign a volume name with the option -V . You can move an entire directory structure with tar by executing:
tar cf - dir1 | (cd dir2; tar xf -)

You can move an entire directory structure over the network by executing:
tar cf - dir1 | ssh remote_host "( cd /path/to/dir2; tar xf - )"

If you want to get a dump of your current filesystem to a secondary hard drive, use (as root):
tar -cvzf /dev/hdd /

If you are writing your tarfile to a device that is too small, you can tell tar to do a multivolume archive with the -M option.

You can back up your home directory to a series of floppy disks by executing:
tar -cvMf /dev/fd0 $HOME

If you are doing backups, you may want to preserve the file permissions. You can do this with the -p option. If you have symlinked files on your filesystem, you can dereference the symlinks with the -h option. This tells tar actually to dump the file that the symlink points to, not just the symlink.

Along the same lines, if you have several filesystems mounted, you can tell tar to stick to only one filesystem with the option -l.

Wednesday, September 01, 2010

Recover Your Fedora Core

In case of dual OS, if u install windows (with pre-installed fedora), the boot loader will be lost and fedora become inaccessible. You can recover your Fedora by the following method:
Enter ur first CD of fedora core, reboot it.
Type linux rescue
Then on shell type chroot /mnt/sysimage
grub-install /dev/XXX (choose XXX=sda or hda or hdb as per ur system )
Reboot your Syatem
To know what is XXX type
# /sbin/fdisk -l
u'll see some lines with /dev/XXX , get what is XXX

Tuesday, August 31, 2010

YUM : Proxy authentication cofiguration

You are connected through proxy server which asks for authentication (i.e. username & password). In this case you have to make some configuration to work with YUM. So simply follow these instructions:
open your terminal as root and type:

#gedit .bashrc hit Enter

you can use vim, emac instead of gedit.
Type the following at the end of file:

export http_proxy="http://username:pw@proxyserver:port" 
hit Enter, then save file. close gedit and restart your computer

username & pw is your proxy username & password respectively. proxyserver:port is address of your proxy server with port e.g. export http_proxy="http://mac:jack@10.1.1.18:80"