System Backup module
The system module of the LRS allows to backup and restore (or "make image of") whole partitions of a PC's hard disk regardless of its operating system. The LRS system module relies on a client PC network boot and does not require any specific software installation on the operated PC. Backups can be managed remotely thanks to wake-on-lan and to the LRS web interface.
1. Principles
The backed up PC needs to have a network interface card of PXE type or etherboot compatible. When booted the network interface card takes control of the client PC which will in turn execute a software stored on the server. You may use an etherboot floppy or etherboot cdrom for booting on the network. This enables client PCs to boot even with an erased or corrupt hard disk. When the PC is started, this software offers to users a choice of actions previously defined by the administrator. The choice of actions is :
- Hard disk backup : users back up partitions of a PC's hard disk on the server when PCs are being started.
- Boot on local hard disk : users boot on the hard disk.
- Boot on the floppy disk drive : users boot on the floppy disk drive.
- Boot on the CD-Rom drive : users boot on the CD-Rom drive.
- Recovery of previously backed up images (operating system, application...) : the partitions of the hard disk are recreated. Partition by partition the images are repatriated from the server towards the client. Users thus recover their working environment such as last saved (screan saver, printer device driver...).
Disk backup and recovery is done on boot as programs and operating systems are not writing anything on the hard disk. Hard disks are thus being stable and clean and the file system coherent. A web administration interface enables to visualize and administrate available images as well as the starting of the network's PCs.
2. Performance
As an indication we have noted the required recovery time that corresponds to installations we made on 100 Mbits/s networks :
| Operating system | Size of datas | Recovery times |
| Windows 9X | 200 Mo | 1 to 3 minutes |
| Windows Me | 500 Mo | 2 to 6 minutes |
| Windows NT et 2000 | 500 Mo | 2 to 6 minutes |
| Windows XP | 1,4 Go | 10 minutes |
| Linux (ext 2, ext3, ReiserFS) | Variable | Variable |
The images of the hard disk are saved in a compressed manner on the server.
3. Functions
- boot on the client's PC network,
- management of saved images,
- automatic or manual addition of machines,
- management of user's menus,
- creation of hard disk images,
- automatic backup functions via Wake-on-LAN,
- possibility to generate bootable CDs or DVDs based on the server's images so as to install isolated client PCs.
4. Supported file systems
The following file systems are supported :
- ext2 and ext3
- reiserfs
- xfs
- linux swap.
The difference between the proprietary version of the LRS and the GPL edition is the support of :
- fat16 (dos)
- fat32 (Windows 3.x to Windows Me and XP)
- NTFS (Windows NT, 2000, XP, Windows Server 2003, base partitions, mirror excluding raid software)
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It is always possible to backup other type of partitions. In that case, all sectors are systematically backed up with a compression. That is the method used to backup :
- the hidden partitions of Compaq System Partition for SmartStart,
- jfs.
5. Network interface card
The following PXE network interface card were tested and found to work :
- Intel Ether Express Pro, 3COM905 C, 3COM905TX, motherboard Intel 8255x with controler, network interface card with chipset 8139 and eprom PXE, DLINK530TX and TX+ wwwith eprom PXE, SMC 1211TX.
The following network interface card are supported via a boot on the floppy disk :
- Lance PCI (vmware for ex.), motherboards with chipset SIS900, 3COM900, 3COM905B, 3c905b-tpo100,3COM900b-combo, 3COM905c, cnetwork interface card with chipset Realtek 8029 and 8139, dlink-530tx-old, via-rhine, smc1211, Dlink DFE 538, Intel 82559er, eepro100, 82562em.
6. PCs with SCSI cards
Most pcs with SCSI cards will be backup and restored without problems. In some rare case, the kernel that is booted on the pc for backing up the machine may not recognise the SCSI card. In this case, a new diskless kernel must be built.
7. More information
You will find more documentations of the product on our commercial web site:
