How to replace a hard drive...

[William Park]

On Wed, May 04, 2011 at 06:25:05PM -0400, Peter King wrote:
> A little while ago I had a Western Digital Caviar Black drive that was throwing
> bad sector errors. On the view that storage is cheap and reliability is crucial,
> I replaced it with a fresh shiny new hard disk (a 1TB Seagate Barracuda), and one
> way or another managed to restore all the data that was on the damaged disk.
> 
> This left me with the WD disk. So I tried reformatting it, which should lock out the
> bad sectors. That seems to work: once reformatted, it passes fsck with no problem,
> and it has fast access times.
> 
> Here's the first question. Can I trust this drive now?

No.  I'm using my "bad" disk to try out latest distros.

> 
>   (I'm inclined to think the answer should be no, on the grounds that once a drive
>    goes bad it should never be trusted again. But more experienced hands should
>    tell me what they think.)
> 
> One thing I noticed while fooling around with the drives is that my root partition
> is on what nowadays counts as a low-capacity drive (a "mere" 320GB). So I thought
> I'd find out how easy or hard it would be to transfer it to a new and larger hard
> drive.
> 
> So the first thing I tried was to dd everything (including the MBR) over to a new
> drive, and then to resize the root partition on the new disk with GParted. No go. 
> GParted wouldn't do it, claiming that things didn't end on cylinder boundaries and 
> that was over. It reminded me why I strongly prefer command-line tools.

You must have "old" version.  I get that kind of error when I
partitioned using sectors, and program expects in C/H/S.

> 
> The second thing I tried was to simply partition the new drive along the lines of
> the way the old drive was partitioned (namely a boot partition, swap partition, root 
> partition) using all of the new disk, and, once the partitions are properly formatted,
> then transfer the files on the boot/root partitions using, let's see if I have this
> right,
> 
>     find . -xdev | cpio <destination> 
>     
> from the source. That worked. Then I tried to copy over the boot sectors of the MBR
> without copying the partition table, using:
> 
>     dd if=/dev/sda of=/dev/sdb bs=446 count=1
> 
> But on boot, I just get GRUB GRUB GRUB GRUB... endlessly filling the screen. Drat.

Yes, that would not work.  You need to re-install GRUB.

> Now I confess I cheated; I tried to boot from the new disk "in place" attached via
> USB, rather than physically replacing the old boot/root disk, and perhaps that's
> the problem. (Note: I don't see why, since if the drive address is wrong GRUB should
> just give me a standard failure, like "no kernel detected" or the like.) The struggle
> is, well, ongoing.

It may be that the order of disks your computer sees is not what you
expect.

> 
> So here's the second question. Is there a more sensible/straightforward way to reproduce
> one disk onto another of larger size?

You should be able to "dd" the whole disk, and then adjust the last
primary or extended partition.  Then, re-install boot loader.
-- 
William
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