hd copy with dd

[thecooptoo]

HD is failing so i want to make a copy of it onto a new HD
ie

[frostschutz]

It's better to copy the partitions, since it's easier to create partitions of the same size, rather than getting same-sized HDDs. Besides, this way you can choose what to copy first (personal data partition before system data partition), and what not to copy at all (swap partition).

If the source device is failing, it's better to add error conversion options to dd:

[thecooptoo]

[frostschutz]

I think it's actually better to copy the whole partition, rather than the files. This is because when copying a partition, the hard disk doesn't have to do any seeking - it can just keep reading data on and on. When copying files, it always first has to seek to the beginning of the file before it can start reading it. This is a lot of unnecessary extra work for a dying hard disk... What's more, copying files works only on the file system layer, which may not be able to handle disk errors as "smoothly" as a raw stream reader like dd does.

If you still want to copy files rather than partition for some reason, a common way would be to use plain old cp -a or tar -p.

[thecooptoo]

[morodoch]

You could always try partimage, booting from a rescue CD with both hard drives attached.

http://www.partimage.org/

I use the system rescue cd:

http://www.sysresccd.org/

I used to use knoppix for such things, but the sysresccd is based on gentoo, and has a closer match to the gentoo install for things like lvm and such.
_________________
Well, the Sister was right. You boys could use a little churching up. Slide on down to the Triple Rock, and catch Rev. Cleophus. You boys listen to what he's got to say.

-- Curtis

[thecooptoo]

I was going to try and cp the stuff across.

[morodoch]

What does

[thecooptoo]

[morodoch]

I see what your problem is - hdb3 is just a file & that's why you ran out of space.

It should be a block device (with a "b" in the first column).

You've copied your partition to a normal file in /dev.

I'm not sure why there is no device file there! what does ls -l /dev/hdb* show?
_________________
Well, the Sister was right. You boys could use a little churching up. Slide on down to the Triple Rock, and catch Rev. Cleophus. You boys listen to what he's got to say.

-- Curtis

[thecooptoo]

[morodoch]

[thecooptoo]

[morodoch]

OK, the permissions are a bit wrong, but you should still be able to do your dd as root.
_________________
Well, the Sister was right. You boys could use a little churching up. Slide on down to the Triple Rock, and catch Rev. Cleophus. You boys listen to what he's got to say.

-- Curtis

[thecooptoo]

[morodoch]

Well that *is* odd - I guess that somehow your kernel may have lost visibility of the device. Does cfdisk still work on hdb? Maybe a reboot is in order...
_________________
Well, the Sister was right. You boys could use a little churching up. Slide on down to the Triple Rock, and catch Rev. Cleophus. You boys listen to what he's got to say.

-- Curtis

[thecooptoo]

cfdisk /dev/hdb givers a blank screen with this at the bottom of the page

FATAL ERROR: Bad primary partition 2: Partition ends after end-of-disk
Press any key to exit cfdisk

but

[morodoch]

How much hassle would it be to recreate the partition table on hdb, and start again? (It is hdb you're copying *to*, isn't it?)

It sounds like your partition table has been corrupted. If you don't mind starting from scratch, I suggest this:

1. zero out your partition table with

[thecooptoo]

Ive been wondering whether to just start again

Thanks for the help . I'll let you know how I get on
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[thecooptoo]

with the new HD as a slave I deleted the old partitions and recreated them . cfdisk now reads the new partitions

[morodoch]

This is *really* weird.

Is this what your /dev/hd* looks like after a reboot?
_________________
Well, the Sister was right. You boys could use a little churching up. Slide on down to the Triple Rock, and catch Rev. Cleophus. You boys listen to what he's got to say.

-- Curtis

[thecooptoo]

reboot sorted it

[frostschutz]

No, you don't need to copy swap partitions.

[morodoch]

You just need to mkswap the new swap partition.

If you can mount both the old partition and the new partition, you should be able to do something like this to copy the files over:

[thecooptoo]

thanks

what NOT to do is

cp -Rp / /mnt/newdisk

it copies all the symlinked files as well ( I did RTFM but clearly didnt understand it )

I'll have another go tomorrow
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