DRBL
Encyclopedia
DRBL is a NFS-/NIS
server providing a diskless or systemless environment for client machines.
It could be used for
Providing a DRBL-Server
Installation is possible on a machine with Debian
, Ubuntu
, Mandriva
, Red Hat Linux
, Fedora
, CentOS
or SuSE already installed. Unlike LTSP
, it uses distributed hardware resources and makes it possible for clients to fully access local hardware, thus making it feasible to use server machines with less power. It also includes Clonezilla
, a partitioning and disk cloning utility similar to Symantec Ghost.
DRBL comes under the terms of a GPL license so providing the user with the ability to customize it.
Disk Cloning
Clonezilla
(packaged with DRBL) uses partimage
to avoid copying free space, and gzip
to compress Hard Disk images. The stored image can then be restored to multiple machines simultaneously using Multicast
packets, thus greatly reducing the time it takes to image large numbers of computers. The DRBL Live CD allows you to do all of this without actually installing anything on any of the machines, by simply booting one machine (the server) from the CD, and PXE
booting the rest of the machines.
Hybrid Client
An excellent way to make use of old hardware. Using old hardware as Thin Clients is a good solution, but has some disadvantages that a Hybrid Client can make up for.
DRBL allows you to set up multiple Hybrid Clients with relative ease.
provided by the DRBL server via tftp, and proceeds to map an nfs
share (also provided by the DRBL server) as its root (/) partition. From there, the client boots either the linux distribution on which the DRBL server is installed, Clonezilla, or an installer for various Linux distributions, depending on how that particular client was configured on the DRBL server.
All system resources reside on the local machine except storage, which resides on the DRBL server.
Network Information Service
The Network Information Service, or NIS is a client–server directory service protocol for distributing system configuration data such as user and host names between computers on a computer network...
server providing a diskless or systemless environment for client machines.
It could be used for
- cloning machines with ClonezillaClonezillaClonezilla is a free disaster recovery, disk cloning, disk imaging and deployment solution. Clonezilla is designed by Steven Shiau and developed by the NCHC Free Software Labs in Taiwan...
software inbuilt, - providing for a network installation of Linux distributions like Fedora, Debian, etc.,
- providing machines via PXE boot (or similar means) with a small size operation system (e. g. DSL, Puppy Linux, FreeDOS).
Providing a DRBL-Server
- Installation on a machine running a supported Linux distribution via installation script,
- Live CDLive CDA live CD, live DVD, or live disc is a CD or DVD containing a bootable computer operating system. Live CDs are unique in that they have the ability to run a complete, modern operating system on a computer lacking mutable secondary storage, such as a hard disk drive...
.
Installation is possible on a machine with Debian
Debian
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
, Ubuntu
Ubuntu (operating system)
Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...
, Mandriva
Mandriva
Mandriva S.A. is a publicly traded Linux and open source software company with its headquarters in Paris, France and development center in Curitiba, Brazil. Mandriva, S.A...
, Red Hat Linux
Red Hat Linux
Red Hat Linux, assembled by the company Red Hat, was a popular Linux based operating system until its discontinuation in 2004.Red Hat Linux 1.0 was released on November 3, 1994...
, Fedora
Fedora (operating system)
Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...
, CentOS
CentOS
CentOS is a free operating system based on Red Hat Enterprise Linux . It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution...
or SuSE already installed. Unlike LTSP
Linux Terminal Server Project
Linux Terminal Server Project is a free and open source terminal server for Linux that allows many people to simultaneously use the same computer. Applications run on the server with a terminal known as a thin client handling input and output...
, it uses distributed hardware resources and makes it possible for clients to fully access local hardware, thus making it feasible to use server machines with less power. It also includes Clonezilla
Clonezilla
Clonezilla is a free disaster recovery, disk cloning, disk imaging and deployment solution. Clonezilla is designed by Steven Shiau and developed by the NCHC Free Software Labs in Taiwan...
, a partitioning and disk cloning utility similar to Symantec Ghost.
DRBL comes under the terms of a GPL license so providing the user with the ability to customize it.
Features
DRBL excels in two main categories.Disk Cloning
Clonezilla
Clonezilla
Clonezilla is a free disaster recovery, disk cloning, disk imaging and deployment solution. Clonezilla is designed by Steven Shiau and developed by the NCHC Free Software Labs in Taiwan...
(packaged with DRBL) uses partimage
Partimage
Partimage is a disk cloning utility for Linux/UNIX environments. Partimage can save partitions in many formats to a disk image. Utilities such as Partimage are useful in a number of situations which are commonly encountered by network administrators as well as advanced computer users who maintain...
to avoid copying free space, and gzip
Gzip
Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv and Huffman coding...
to compress Hard Disk images. The stored image can then be restored to multiple machines simultaneously using Multicast
Multicast
In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source creating copies automatically in other network elements, such as routers, only when the topology of the network requires...
packets, thus greatly reducing the time it takes to image large numbers of computers. The DRBL Live CD allows you to do all of this without actually installing anything on any of the machines, by simply booting one machine (the server) from the CD, and PXE
Preboot Execution Environment
The Preboot eXecution Environment is an environment to boot computers using a network interface independently of data storage devices or installed operating systems.PXE was introduced as part of the Wired for Management framework by Intel and is described in the specification The Preboot...
booting the rest of the machines.
Hybrid Client
An excellent way to make use of old hardware. Using old hardware as Thin Clients is a good solution, but has some disadvantages that a Hybrid Client can make up for.
- Streaming Audio/Video - A Terminal ServerTerminal serverA terminal server enables organizations to connect devices with an RS-232, RS-422 or RS-485 serial interface to a local area network . Products marketed as terminal servers can be very simple devices that do not offer any security functionality, such as data encryption and user authentication...
must decompress, recompress, and send video over the network to the client. A Hybrid does all decompression locally, and can make use of any graphics hardware capabilities on the local machine. - Software that requires real-time input - Since all input at a thin clientThin clientA thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...
is sent over the network before it is registered by the operating system, there can be substantial delay. This is a major problem in software that requires real-time input (i.e. video games). Hybrid clients run the software locally, and as such, do not have this problem.
DRBL allows you to set up multiple Hybrid Clients with relative ease.
How it works
The client computer is set to boot from the network card using PXE or Etherboot. The client requests an IP address, and tftp image to boot from, both are provided by the DRBL server. The client boots the initial RAM diskInitrd
In computing, initrd is a scheme for loading a temporary file system into memory in the boot process of the Linux kernel. initrd and initramfs refer to slightly different methods of achieving this...
provided by the DRBL server via tftp, and proceeds to map an nfs
NFS
NFS may mean:* Network File System , the Network File System protocol developed by Sun Microsystems* NFS , a former Icelandic television news service* National Financial Switch, a bank network in India...
share (also provided by the DRBL server) as its root (/) partition. From there, the client boots either the linux distribution on which the DRBL server is installed, Clonezilla, or an installer for various Linux distributions, depending on how that particular client was configured on the DRBL server.
All system resources reside on the local machine except storage, which resides on the DRBL server.