Softpanorama

Home Switchboard Unix Administration Red Hat TCP/IP Networks Neoliberalism Toxic Managers
May the source be with you, but remember the KISS principle ;-)
Skepticism and critical thinking is not panacea, but can help to understand the world better

GNU ddrescue

News See also Recommended Links Books Faqs RFCs  
DD Ghost Minimalistic Linux Distributions   History Humor Etc

 GNU ddrescue. This is the best utility for grabbing data off a failing hard drive. It is fast for a dd-based command, and smart enough to skip over bad blocks and keep going, looking for good blocks to copy.

The most surefire method I know requires a second local hard drive of equal or greater size; either SATA/PATA or USB. Then boot up SystemRescue and copy the first drive to the second drive. Of course you must replace the drive names in the example with your own drive names:

# ddrescue /dev/sda /dev/sdb

You may copy partitions instead of whole drives. Then run fsck on the second drive to check for and fix errors. Make sure it is not mounted, then run this command:

# fsck /dev/sdb

Add the -a option to tell fsck to automatically fix all errors. Use fsck only on Linux filesystems. For other filesystems you'll need their own native filesystem-consistency-fixing utilities.

Don't confuse GNU ddrescue with dd-rescue. They do the same thing and both do it well, but I think ddrescue is faster and more reliable.

GParted is the best partitioning and filesystem-creation application there is. Put it on a bootable medium and you can manage most Linux, Unix, Mac OS X, or Windows partitions and filesystems. Add the dd-based Clonezilla for cloning, and you have the ultimate power tool for new installations, restores, and replications. Clonezilla is an intelligent partition or disk-cloning program that works on any filesystem, because it operates at the block level. On supported filesystems (which are pretty much the same batch as GParted) it copies only used sectors. On unsupported filesystems it can't tell which ones are used, so it does a block-by-block copy. Either way you get your clones.

Fixing Horked MBRs

When you're multi-booting or installing a new operating system onto a used system, sometimes the MBR (Master Boot Record) gets all messed up, so you need to wipe it out and start over. You can do this with the dd command. Be sure to use your own drive name for the of= value:

# dd if=/dev/zero of=/dev/hda bs=446 count=1

That preserves the partition table. If you also want to zero out the partition table, do this:

# dd if=/dev/zero of=/dev/hda bs=512 count=1

S: backup boot partition, bootsector

Usage

        # save MBR
        dd if=/dev/hda of=/export/sysbaks/hda-img.mbr bs=512 count=1
        dd if=/dev/hdb of=/export/sysbaks/hdb-img.mbr bs=512 count=1

        # save C: boot
        dd if=/dev/hda3 of=/export/sysbaks/hda-img.btc bs=512 count=1
        dd if=/dev/hdb3 of=/export/sysbaks/hdb-img.btc bs=512 count=1

Help

you can use lilo.conf specifying the boot partition or you can simply use dd to work with bootsectors. for example, to make a backup copy of a bootsector in a partition, say, hda1, you could do:

dd if=/dev/hda1 of=bootsect.hda1 bs=512 count=1

if you want to recover later you do:

dd if=bootsect.hda1 of=/dev/hda1 bs=512 coount=1

in the same way you could copy hda1 bootsector to hda2 bootsector:

dd if=/dev/hda1 of=/dev/hda2 bs=512 count=1

Patrick Machado


Ghost Linux

Newsgroups: comp.os.linux.misc
 

> Does anyone know of a program that will ghost Linux in the same way as
> Norton Ghost works in Windows?

Yes , Ghost will work. I use Ghost to ghost machines with Linux and Windows preinstalled.

Rafael


Ghost Linux

cpio? afio? tar? These are archiving programs, and work at the filesystem level (meaning they're not quite like Ghost, but they're still excellent for backing up data.)

If you want to make an "image backup" then you use dd. dd works at the raw device level, making a sector-by-sector copy of a disk. You can make an exact copy of a hard disk by doing: dd if=/dev/hda of=somewhere bs=8192
which copies everything on the hard disk at /dev/hda to "somewhere". "somewhere" can be on a remote server, naturally. You should bzip2 it once it's there, to reduce time taken by the next step.

You can re-create the original image on /dev/hda by booting from a Linux floppy that has enough smarts to mount the remote server via NFS or Samba and also has bunzip2 and dd. This Linux boot floppy would do something very similar to:
mount -t smb //remoteserver/images /mnt dd if=/mnt/linuxhdaimage.bz2 | bunzip2 -dc | dd of=/dev/hda

There's got to be a better way to do that, though. "rsync" would not chew up nearly so much network bandwidth, but it might have problems with things that require absolute positioning on disk like the MBR, the kernel image, and the loading map. I suppose you could combine the approaches, using dd to recover the MBR and /boot, then using rsync to fix everything else. This would require a separate /boot partition, naturally, but most people have that.

Please note that I have never tried the more complex versions of this. I did use dd and a bootdisk to back up and restore my entire laptop once, but that was it. Take with several grains of salt....

Matt G


Recommended Links

Google matched content

Softpanorama Recommended

Top articles

Sites

Creating a Backup of System Partitions Using WinHex

Partition Image for Linux

Storix Backup Administrator for Linux and AIX - Prices



Etc

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotesSomerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose BierceBernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOSProgramming Languages History : PL/1 : Simula 67 : C : History of GCC developmentScripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-MonthHow to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haterís Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D


Copyright © 1996-2018 by Dr. Nikolai Bezroukov. www.softpanorama.org was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) in the author free time and without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.

FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.

This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...

You can use PayPal to make a contribution, supporting development of this site and speed up access. In case softpanorama.org is down you can use the at softpanorama.info

Disclaimer:

The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.

The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Last modified: April 30, 2018