Linux – Drive cloning dd or rsync/sync via KVM

data-recoverydddisaster-recoverylinuxrsync

I've got a crash and the system won't boot correctly. I am getting errors like:

ata3.00: status: { DRDY }
ata3.00: status: { UNC }

What would be the best way to save the main drive to make the system boot again?

I am looking at:
Using DD for disk cloning

I read that using DD to clone a live system is bad. But does booting in via KVM mean just as bad?

Best Answer

You don't want to do a block level copy of a drive when any of the filesystems are mounted (which also means that you can't be running the OS installed on the drive). Either boot a live CD/USB (I like RIPLinux) or connect the drive to another machine.

In terms of getting data off a dodgy drive, rather use ddrescue (the GNU version, sometimes called gddrescue). It won't stop as soon as it encounters a bad sector like dd will, and can resume copies. Make sure to specify a log file:

ddrescue /dev/sda /mnt/sdb1/sda.img /mnt/sdb1/sda.log
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