Posted on 20-08-2009
Filed Under (linux, networking, security, ubuntu, windows) by admin

VNC is considered to be an insecure protocol. The password is sent using fairly weak encryption, and the rest of the session is not encrypted at all. For that reason, when using VNC over an untrusted network or internet, I recommend you tunnel it over SSH.

To forward VNC port 5900 on localhost to remote host port 5900

ssh -L 5900:localhost:5900 vncserver

If your ssh server is listening on other port like: 222

ssh -L 5900:localhost:5900 vncserver -p 222

The same procedure can be done on a window$ machine using putty Read the rest of this entry »

Comments Off    Read More   
Posted on 19-08-2009
Filed Under (linux, ubuntu) by admin

tar is a compression utility that allows you to compress files and backup up your system.
Here are some useful tar commands to backup and restore files.
if you want to backup the content of /home and /etc:

tar cvpf /mnt/backup/tarball_bakup /home /etc

Once you have a full backup of your system you could do incremental backups using the –newer option, which backs up everything that has changed since the specified date

tar cvpf /mnt/backup/tarball_backup --newer 19Aug09 /home /etc

when things go wrong and you want to restore the content of backup

tar xvpf /mnt/backup/tarball_backup home/user

Sometimes you accidentally deleted a file; therefore, you only need to restore a single file. Remember when restoring from a tar archive, there’s no absolute path, in other words, tar removes all the leading slash “/” so /home/user/file1 becomes home/user/file1. And you should be in the / “root” directory.

tar xvpf /mnt/backup/tarball_backup home/user/shell1.sh

What about if you don’t know the exact name of the file but only part of the file name

tar tvpf /mnt/backup/tarball_backup | grep shell*

or

tar tvpf /mnt/backup/tarball_backup | more

to page trhough the backup file.

Here’s a good shell script  that performs monthly, weekly, and daily backus to a tgz file. Read the rest of this entry »

Comments Off    Read More   
Posted on 19-12-2008
Filed Under (linux, ubuntu) by admin

Recently I had to install ubuntu on a machine with a bad cdrom drive, which made me look for alternative ways of installing ubuntu. This article describes two ways of how to install Ubuntu by copying the content of the installation CD to an USB drive such as a memory stick (or flash drive) and making the USB stick bootable. This is handy for machines like ultra portable notebooks that do not have a CD drive but can boot from USB media. On a side note, I have to point out that booting from USB stick can be very handy, but there is no guarantee that it will work with your particular combination of computer and USB stick. Even if you are able to boot from your USB stick on one computer, this does not mean that it is going to work with the next one. You can try experimenting with different settings in your PC’s BIOS to make it work.
Read the rest of this entry »

(2) Comments    Read More   
Posted on 25-09-2008
Filed Under (linux, security, ubuntu) by admin

After having to reset my Ubuntu box password, I decided to come up with this tutorial on how to reset linux password, in this case we will be taking two different methods…

Read the rest of this entry »

Comments Off    Read More