dd + gparted + UUID

NoOp glgxg at sbcglobal.net
Sun Nov 29 23:59:35 UTC 2009


Ran into an interesting problem today; I was given a pair of 200Gb hard
drives this week to replace my 40Gb drives. On the first machine I went
the dd route of copying all of the files from the 40Gb to the 200Gb. Got
everything converted w/o issue (well, other than having to run Supergrub
to get the grub sorted out afterwards).

On the second machine I used gparted to copy the 40Gb to the other 200Gb
drive. Again, no problems & used Supergrub to get grub sorted out
afterwards).

I was also given a nifty usb-sata-ide adapter from vantec:
<http://www.vantecusa.com/front/product/view_detail/266>
Cool little device.
$ lsusb
Bus 001 Device 003: ID 152d:2338 JMicron Technology Corp. / JMicron USA
Technology Corp. JM20337 Hi-Speed USB to SATA & PATA Combo Bridge

Now for the problem. I noticed that I couldn't bring up the 40Gb drive
from the first machine on the same machine with the new 200Gb drive via
the usb-ide adapter. The drive would connect (via the usb adapter) to
any of my other machines. I just would not connect to the machine it
came out of. I fiddled with the USB choices in bios, tried on two other
machines with identical motherboards (exact same machines) bios etc. No
luck. I then took a look at the uuid on the 200Gb that I'd dd'ed & sure
enough it was exactly the same as the uuid of the 40Gb that I'd copied
the data from. Duh.

Now for the fix. I connected the 40Gb to another machine, unmounted it,
and used:

$ sudo tune2fs -U random /dev/sdc1

to change the uuid. I then plugged it back into it's original machine &
sure enough it automounted with out any further issue. On the 2nd
machine that I used gparted to copy the 40Gb to that 200Gb I ran into
the exact same problem.

So, if any of you run across a similar situation you might check the
uuid's & modify the extricated drive's uuid using the above.

Added note: dd & gparted did what they were designed to do; copy the
drive bit for bit, so they are not at issue. I'm just posting this so
that other folks will know that is the case in the event they run into
to the same issue.
  In the meantime I plan to 'clean up' my nearly 40Gb's of 'stuff' that
I copied over to the 200Gb's... makes one wonder when 40Gb is too small
- reminds me of my over-stuffed garage. Unfortunately I doubt someone
will give me a 200Gb garage... :-(






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