LinuxQuestions.org
Help answer threads with 0 replies.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices

Reply
 
Search this Thread
Old 04-30-2006, 02:10 PM   #121
sfrazier9999
LQ Newbie
 
Registered: Jan 2006
Posts: 3

Rep: Reputation: 0

Is it possible to dd an image of your hard disk to a dvd cdrom?

dd if=/dev/hdc of=/dev/cdrom
 
Old 04-30-2006, 07:05 PM   #122
AwesomeMachine
Senior Member
 
Registered: Jan 2005
Location: USA and Italy
Distribution: Debian jessie/sid; OpenSuSE; Fedora
Posts: 1,593

Original Poster
Rep: Reputation: 162Reputation: 162
Post Image to DVD

Quote:
Originally Posted by sfrazier9999
Is it possible to dd an image of your hard disk to a dvd cdrom?

dd if=/dev/hdc of=/dev/cdrom
Dd will not write directly to optical type drives, like CD/DVD. It is possible to put hard drive contents on a DVD, but it doesn't work the way you think it would. People think if you just booted the DVD of a hard drive image of their linux installation they will have a whole linux install on a DVD. It doesn't work that way. DVD media is not writable by the kernel, so all the writing that needs to be done has to be done to system memory when using a boot DVD. It is a little more complicated than just making an image of an HDD and using cdrecord to burn it. There are instructions all over the internet on how to make a linux live CD. It actually isn't that hard to even make Knoppix.

If you were thinking of using a DVD for backup, there are programs to write a system to one or more DVD's, and restore them from a bootable CD if the system fails.
 
Old 05-09-2006, 04:08 AM   #123
Bongoots
LQ Newbie
 
Registered: May 2006
Location: Oxford, UK.
Distribution: Gentoo
Posts: 5

Rep: Reputation: 0
What steps do I need to follow to make a perfect copy of a DVD with an unknown filesystem, with the hopeful purpose of being able to put the raw data back onto another DVD?

I've already done this:

dd if=/dev/hdc of=image.raw

Would I have needed to use bs or count? How would I get these values in the first place?

Now how would I get this back onto a blank DVD? Would there be any concerns about the difference in size of the original and blank DVDs?

Last edited by Bongoots; 05-09-2006 at 04:14 AM.
 
Old 05-11-2006, 12:02 AM   #124
AwesomeMachine
Senior Member
 
Registered: Jan 2005
Location: USA and Italy
Distribution: Debian jessie/sid; OpenSuSE; Fedora
Posts: 1,593

Original Poster
Rep: Reputation: 162Reputation: 162
Post Optical drives are a big pain with dd.

You have your DVD image file. I'm assuming you run a graphical desktop environment such as KDE or Gnome. When you say exact I take that to mean the data and any boot information. To make an absolutely identical DVD is a little more tricky because there are several places where information about the author, the date, organization, copyright, etc can be stored. The DVD burning program will burn the image back to the DVD, and it will work exactly the same as the DVD it was made from, but it won't be bit for bit identical in the first few sectors. That is really unimportant for functional copying. The most trouble free program for burning images to a DVD is k3b. You probably already have it on your system. You want to burn a DVD image - Tools > DVD > Burn DVD ISO Image. It should just work.
 
Old 05-11-2006, 03:15 AM   #125
Bongoots
LQ Newbie
 
Registered: May 2006
Location: Oxford, UK.
Distribution: Gentoo
Posts: 5

Rep: Reputation: 0
Cheers for the reply

I failed to say that I know my stuff about Linux, as I've been using it for 5 years now and am currently using Gentoo.

Apart from being a perfectly exact copy of the DVD with all the minor details, the method I used should get me the boot+data areas? (i.e. `dd if=/dev/dvd of=image.raw`)

There's no need for bs/count to be set?

I'll try out a burn with k3b to see if it works on the weekend, but will have to wait til Monday to try it out.
 
Old 05-11-2006, 03:47 AM   #126
AwesomeMachine
Senior Member
 
Registered: Jan 2005
Location: USA and Italy
Distribution: Debian jessie/sid; OpenSuSE; Fedora
Posts: 1,593

Original Poster
Rep: Reputation: 162Reputation: 162
Arrow Bs/count

If sector size is divisible, or a multiple of 512 bytes, you can just use the default block size of 512 bytes by not specifying "bs" at all. DVD sectors are 2048 bytes, or exactly 4 * 512 bytes. For faster copying you might try bs=4096, so you don't have so many I/O's. Dd is a buffer intensive program. All the data has to be buffered 4 times. Once in the source drive internal buffer, once in the dd read buffer, once in the dd write buffer, and once in the destination drive buffer. That's four I/O's for every block. You can see where picking a proper block size can really improve performance. If "count" is not used, dd stops when it gets to the end of the media, and marks the file it created with an EOF.
 
Old 05-11-2006, 12:00 PM   #127
Bongoots
LQ Newbie
 
Registered: May 2006
Location: Oxford, UK.
Distribution: Gentoo
Posts: 5

Rep: Reputation: 0
If sector size is divisible, or a multiple of 512 bytes [...]

This isn't a typical audio / video / data disc, so I can't be sure of the value without checking first.

How would I get this value? (considering I can't mount the DVD)
 
Old 05-11-2006, 03:44 PM   #128
AwesomeMachine
Senior Member
 
Registered: Jan 2005
Location: USA and Italy
Distribution: Debian jessie/sid; OpenSuSE; Fedora
Posts: 1,593

Original Poster
Rep: Reputation: 162Reputation: 162
Post

Quote:
Originally Posted by Bongoots
If sector size is divisible, or a multiple of 512 bytes [...]

This isn't a typical audio / video / data disc, so I can't be sure of the value without checking first.

How would I get this value? (considering I can't mount the DVD)
If it is a bootable DVD, with programs on it, it is a data DVD. I can't imagine any DVD that wouldn't be a typical audio, video, or data disk; except perhaps a game DVD. Dd won't work with anything but data. Audio has no format, it is just a continuous track demarkated into smaller tracks. Video is mpeg, so you can dd video disks, but games are special. Games require special software to copy because the format on the disk changes, and there are unformatted parts of a game disk which dd cannot deal with.
 
Old 05-12-2006, 02:54 AM   #129
Bongoots
LQ Newbie
 
Registered: May 2006
Location: Oxford, UK.
Distribution: Gentoo
Posts: 5

Rep: Reputation: 0
Not audio, not video, not data, not game.. it's a disc with a Mac filesystem on it (I am led to believe).

So I should have no worries at all?
 
Old 05-12-2006, 03:57 AM   #130
AwesomeMachine
Senior Member
 
Registered: Jan 2005
Location: USA and Italy
Distribution: Debian jessie/sid; OpenSuSE; Fedora
Posts: 1,593

Original Poster
Rep: Reputation: 162Reputation: 162
Post

Quote:
Originally Posted by Bongoots
Not audio, not video, not data, not game.. it's a disc with a Mac filesystem on it (I am led to believe).

So I should have no worries at all?
I don't think the DVD authoring program, k3b, will do well with that. Could you please report back and tell us what happened?
 
Old 06-04-2006, 09:35 AM   #131
Borkowski
LQ Newbie
 
Registered: Sep 2001
Location: CT, USA
Distribution: CRUX Linux; OpenBSD; ARCH Linux
Posts: 22

Rep: Reputation: 15
Of course it is very useful. Thanks.
 
Old 06-05-2006, 02:32 AM   #132
Bongoots
LQ Newbie
 
Registered: May 2006
Location: Oxford, UK.
Distribution: Gentoo
Posts: 5

Rep: Reputation: 0
I no longer have access to the Mac G5 with a DVD drive, and so unless I buy one myself.. there's no chance of me testing out the raw image I made
 
Old 06-20-2006, 09:25 AM   #133
VirtualM
LQ Newbie
 
Registered: Jun 2006
Posts: 2

Rep: Reputation: 0
Is it possible to create an exact duplicate from a hard disk protected by Safeguard Easy (a hard disk encryption tool)?
Safeguard Easy (from Utimaco) creates two partitions, one for the boot protector and another partition which is encrypted. I believe my problem lies in the unmountability of the second partition as Linux doesn't recognize the (encrypted) file system.

FYI, I'm pretty new to linux and trying to get a better understanding in forensics using Linux tools.
 
Old 06-20-2006, 11:11 AM   #134
Matir
Moderator
 
Registered: Nov 2004
Location: San Jose, CA
Distribution: Ubuntu
Posts: 8,507

Rep: Reputation: 118Reputation: 118
You could create an exact duplicate of the disk, but it will still be encrypted data.
 
Old 06-20-2006, 04:54 PM   #135
VirtualM
LQ Newbie
 
Registered: Jun 2006
Posts: 2

Rep: Reputation: 0
Quote:
You could create an exact duplicate of the disk, but it will still be encrypted data.
But how can I make a duplicate if I can't mount it? Isn't mounting the partition necessary?

Of course the duplicate would still be encrypted, otherwise it wouldn't be a duplicate.
 
  


Reply

Tags
backup, best, clonezilla, cloning, command, data, dd, disk, drive, duplicate, erase, explanation, formatting, ghost, hard, image, iso, memory, ping, popular, recover, recovery, rescue, search, security, stick, upgrade, usb, wipe


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Learn The DD command AwesomeMachine Linux - Newbie 17 08-17-2006 04:22 AM
The best way to learn? iz3r Programming 7 02-06-2005 11:00 PM
Best way to learn Linux from the command line patpawlowski Linux - General 2 03-01-2004 03:37 PM
I want to learn C. KptnKrill Programming 14 12-18-2003 01:03 PM
Best way to learn.... InEeDhElPlInUx Linux - Newbie 5 10-11-2003 01:02 AM


All times are GMT -5. The time now is 03:40 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration