Disk image with dd

Samsara · 01-20-2007, 10:08 AM

When I make an image of a drive to a file, using, say,

dd if=/dev/hda of=/mounted_usb_drive/hda.img

Is the file size going to be the same as the size of the drive at hda? If so, is there a better way of cloning a drive for recovery purposes? In this instance, probably about 30GB of 80GB are actually in use, but the drive contains an XP recovery partition and two Win XP partitions; the recovery partition may also contain the inbuilt DVD player (this is a multimedia-type laptop) which I have no other recovery for, to my knowledge (or it may live on its own little ROM?).

The point is to remove Windows and try Linux without burning myself (if it doesn't work, I should be able to just clone back the image).

Many thanks,

Samsara
.

The Headacher · 01-20-2007, 10:21 AM

I'm not sure about imaging a disk, but I occasionally use partimage to make an image of a partition. It can be found on several livecd's amongst which the System Rescue CD

pwc101 · 01-20-2007, 10:28 AM

You could pipe the output of the dd command into gzip to make a compressed image. This is the way I do my backups and a 6GB partition is reduced to ~2GB:

Code:

dd if=/dev/hda | gzip > /mnt/hdb1/system_drive_backup.img.gz

And to restore:

Code:

gzip -dc /mnt/hdb1/system_drive_backup.img.gz | dd of=/dev/hda

Obviously, compressing the image takes longer, but does result in smaller backups. Refer to the wiki article for more info: http://wiki.linuxquestions.org/wiki/Dd

edit: it's also worth looking at this thread for a really comprehensive article on the dd command: http://www.linuxquestions.org/questi...postid=1848006