The Linux Rescue Box

Backing up data from your users' workstations is one of the most taxing jobs

for a system administrator, and it gets tougher with more machines, and even

more if multiple OSs are involved. In this article, we will see how to build a

backup box, which will do an image-based backup of workstations and later on

facilitate restoration over the network as well. Plus, it can also be used to do

remote image-based OS deployments on backbone machines across the

organization.For this, we are using a Linux-based backup system called 'Linux

rescue server'. The software will allow you to take image-based backups of your

Windows XP, Windows 2000/2003 or any UNIX/Linux platform. You can download the

Rescue Server from the link given in the Direct Hit box. You will get an ISO

file, that has to be burnt on a CD using Nero or any other CD writing software.

Make sure you burn it at 4X writing speed.

Installation



To install the Linux rescue server, henceforth called LRS, you will require

at least a P4 machine with 256 MB RAM and 80 GB HDD. Boot this machine with from

the LRS CD you just created. It will ask you to fill in the IP address, Subnet

mask, Gateway, etc.

Then you would be asked to select keyboard layout etc. The installation takes

only 15 minutes. Remove the CD and restart the machine and your LRS is ready.

To configure LRS, take another machine connected on the same Subnet and from

a browser type in the IP address http://:1000.

Give username as 'root' and password as 'linbox' and you will be taken to its

management interface.

Configuring DHCP settings



As our rescue server uses PXE (Preboot eXecution Environment) for backing up

and restoring workstation data, you need to configure a DHCP server on it. If

you already have a DHCP server, you simply need to configure your server to

enable network booting of your rescue machine. For exercising the second option,

first disable the LRS DHCP server, from the Webmin 'System/Bootup and shutdown'

module. Click on 'dhcp3- server' and deactivate the 'Start at boot time' option.

Now, on your existing DHCP server, add a few DHCP options in the client

addresses' pool, with your usual DHCP server configuration interface. Set the

'filename' to '/tftpboot/revoboot/bin/ revoboot.pxe'. It sets the network boot

program to load the said file. This option is also usually available as

'BootFileName' under 'Option DHCP 67'.

List of backup images that you can directly burn to a CD/DVD or configure it so that a user can directly restore their workstation over the network via PXE booting

Then, set 'next-server' to the IP address of your LRS. It is usually

available as 'Boot Server Host Name' under 'Option DHCP 66'. Here, give IP

address of your LRS and filename as /tftpboot/revoboot/ bin/revoboot.pxe. If you

don't have a DHCP server, then you can use the rescue server's DHCP feature.

In order to configure DHCP on this server itself, go to the DHCP form from

its Web interface and select 'DHCP server'. Just give the name of the DHCP

server here and leave other fields as default and scroll down to the Add pools

option. Click on this and specify the IP address range for the DHCP and Apply

the changes. Now, click on 'Start DHCP'. This will start the DHCP server on your

network, which will also act as TFTP server.

Taking backups



For taking backup, just boot a workstation from its network card using PXE

boot. On boot, you will get a text-based menu. Select 'Add a client'. Now, you

will be asked for client-name and password, give 'root' as the client-name and

password as 'linbox'. On successful login, you will get another boot menu which

lets you launch the system backups and restorations. Select the option 'Image

creation shared'. This will connect the machine to the Linux rescue server where

all backup images are kept. It will automatically start taking the backup of

machines and once the backup process is over the machines are automatically made

to shutdown.

This is the menu option that users see when they boot their machines using PXE. This is where users can see the images of their machines for restoring or burning to a CD

Managing backups



Once the backup is taken as an image, next step is to configure the image in

such a way that remote workstations can be restored back, easily. In order to do

this, open the administrative console of LRS using a Web browser and go to

'System backup>Image'.

Here, you will be shown the layout of your boot menu and below that you will

see the list of backup images (local or shared) that you have taken. You can

either burn these images on a CD/DVD, or alternatively, you can move the backup

images to the boot menu. This way, when a user workstation is booted from PXE,

the backup image is shown in the boot menu and the user can restore back his/her

machine just by selecting the backup image name, from the boot menu. The

restoration would be done directly from the LRS system over the network.

If you want to create a CD/DVD out of the backup image, just click on Burn

icon given next to the backup image. The system will first create an ISO image

of the entire backup and then you can either burn ISO images directly on that

system or you can later on download the ISO image and burn it on the system

where you have a CD writer. If you want to move the backup image to boot menu,

then go to the image file and click on the upward arrow icon given in the 'To

menu' option. This will move the image file into the list of boot menu.

Then from the Web interface, select the 'Boot menus' tab and you will see the

backup image that you have moved has come into the boot menu list. Click on

Apply button to reflect the changes in the boot menu.

Now when the client workstation boots from the PXE, the boot menu will also

contain the name of the image file that we have configured above. By selecting

that image, the restoration process will be triggered and the workstation will

be restored back to its original state.

This is only one of the useful features of Linbox that we have demonstrated

in this article. There are so many other useful features like inventory

management, file backup etc, that you can explore yourself.