Author: berkeleylugtransferred

“NILFS2 (New Implementation of a Log-Structured File System Version 2) is a very promising new log-structured file system that has continuous snapshots and versioning of the entire file system. This means that you can recover files that were deleted or unintentionally modified as well as perform backups at any time from a snapshot without a performance penalty normally associated with creating snapshots. In addition, there is evidence that NILFS has extremely good performance on SSD drives.”

Source: http://www.linux-mag.com/cache/7345/1.html

Firewalls are a critical component of keeping your machine safe on the Internet.

This tutorial will show you how to create firewall rules from the command line.

Details of the script actions are commented in the script.

Continue reading “Simple firewall script tutorial for the command line.”

Believe it or not, sometimes the display will die on your Linux operating system. You probably have no control over this…..Time to move on and fix the issue without spending hours on Google searching for a half-baked how-to.

If you are in the process of implementing this article on a broken system, chances are that you see a black screen with text. Please follow these steps so that you can get the pretty colors back!

Step 1: Login.

Step 2: Ensure the graphical daemons are not running.

service gdm stop

service kdm stop

Step 3: Run this command:   X -configure

(This will create the following file in your directory: xorg.conf.new)

Step 4: Copy the configuration file to the right place.

mv xorg.conf.new /etc/X11/xorg.conf

Step 5: Restart the display.

service gdm start (for GNOME users.)

or

service kdm start (for KDE users)

or

startx (for everyone else, the elite)

Step 6: If you are still having problems……

Repeat Steps 1 – 4.

We will change the driver to vesa. Vesa is a generic display driver that will work on any video card. I usually use this driver on all my machines because it is stable and never fails.

Use your favorite text editor and open /etc/X11/xorg.conf

Look for a line that says  something like the following :

Driver      “nv”

Driver      “ati”

Driver      “nvidia”

Driver      “intel”
Change the name from what is in quotes to “vesa”.

Example of how it should be after the change:  Driver      “vea”

Save and exit the file and follow step 5.

I have a webserver with a 4GB CF card in a very very small computer. I was trying to come up with ways to reduce writes on this device and I remembered UnionFS. UnionFS can take 1 folder and make it read-only and have all the changes written to another folder. To the user, everything will look the same. This is very good when adding a disk to a computer and your not using LVM.

What I want to do? I want  /tmp,  /var/log, /var/home, and /root to have the changes written to my USB device that is mounted as  /mnt. These directories receive a lot of writes to them.

I copied the following commands to /etc/rc.local so that they are executed when the machine boots:

—————–

mount -t unionfs -o dirs=/mnt/logs=rw:/var/log=ro unionfs /var/log
mount -t unionfs -o dirs=/mnt/filesystem/root=rw:/root=ro unionfs /root
mount -t unionfs -o dirs=/mnt/filesystem/home=rw:/home=ro unionfs /home
mount -t unionfs -o dirs=/mnt/filesystem/tmp=rw:/tmp=ro unionfs /tmp

—————–

Lets make sure everything worked by doing `df -h`:

—————–

/dev/sda1             3.8G  1.6G  2.1G  44% /

unionfs               7.5G  3.3G  3.8G  47% /var/log
unionfs               7.5G  3.3G  3.8G  47% /root
unionfs               7.5G  3.3G  3.8G  47% /home
unionfs               7.5G  3.3G  3.8G  47% /tmp
-----------------
If you want this to be mounted at boot time without
using /etc/rc.local, simply add the following to /etc/fstab:
-----------------
unionfs /tmp unionfs dirs=/mnt/filesystem/tmp=rw:/tmp=ro 0 0
unionfs /home unionfs dirs=/mnt/filesystem/home=rw:/tmp=ro 0 0
unionfs /var/log unionfs dirs=/mnt/logs=rw:/var/log=ro 0 0
unionfs /root unionfs dirs=/mnt/filesystem/root=rw:/tmp=ro 0 0
-----------------
Now all the changes will be written to my USB device and my main CF
cards will not be written to a lot.

What is Mephisto Backup?

This program can do simple backups and syncs over a network or locally.It uses tar and rsync in the background. Mephisto Backup was made with the Java programming language. The key feature of this program is the ability to backup your system to an image and copy it to a Linux Live DVD for future restoration. The user can then take that cd and move his or her system to any PC.

Features:

1. Backup your operating system to a Live CD.

2. Restore your OS from the Mephisto Live CD. The live CD is used by Mephisto Backup to Restore your system only.

3. Displays the size of your backup ISO and TAR file after each backup job is ran.

4. Blank DVD-RW’s.

5. Sync between locations and save backup configurations.

6. Burn the backup image to the live cd within the program.

7. Backup Schedules.

Additional things to mention:

1. This program is great to use in virtual machines because you can easily generate your virtual machine to a restore disc and deploy the image to any computer!

2. A single source for everything that you have to do: Backup -> Create a disc -> Burn. All in a single application!

3. ITS FLOSS!

Links:

Main website.

Google Code.

Sourceforge.

Contact: Phillip Tribble // phillip.tribble@gmail.com