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I have a Lacie enclosure that has a setup with 2 500gb disks configured as 1 drive of 1TB, the only partition created for the whole drive is HFS+ journaled, but the controller in the enclosure is gone and so the drive refuses to mount anymore.

I have been able to remove those two disks from the enclosure and connect them using USB ports and a program called R-studio (Raid recovery program) check that the setup the controller in the enclosure was using was both disks concatenated (Not Striped). And so configuring that option in R-studio I could be able to get back all the information.

But before I got a license for r-studio for just one use, I would rather buying a new 1TB disk and try to write all the information of those two disks in this new one. I can use Mac or linux machines to do it, and I think it should be ok use DD command in linux to concatenate those two drives into the new one in the right order to get it working again in the new disk and I will reformat the old ones, but I am not sure.

So, is it possible in this scenario to write both disks into a new one using DD? Any hints how the command would look?


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this sounds like like JBOD raid mode, try to connect them with mdadm

use command

mdadm /dev/md1 /dev/disk1 /dev/disk2

where disk1 and disk2 are something like sda1 sdb1 or whatever your disks/partitions are

then simply mount the

mount /dev/md1 /mnt/someMounPoint

to access your data.

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Thanks for your answer, just edited the question, the partition created is HFS+ journaled, would it this work then with mdadm? I am not sure, that's why I was thinking of DD. – pedromarce Feb 24 '11 at 13:44
sure linux kernel supports HFS+ fs, there are some issues with larger partitions but your 1TB one should work just fine. Just join the 2 disks in single md array and try to mount it. – Hrvoje Špoljar Feb 24 '11 at 13:52
Thanks again, I'll give it a go. – pedromarce Feb 24 '11 at 14:16

I'm confused as to what you're actually asking for. By controller, do you mean software that came with the drive? Or do you have an enclosure with two physical disks in it concatenated together? And what do you mean by using DD to dump everything into one, that you have another 1 terabyte drive that you're going to copy everything over to? I'm not sure you're using the right terminology for what you hope to do.

If you have one drive with two partitions/volumes, and you're trying to save the data, and one of them is HFS and the other isn't, your best bet is to back up the data to a second drive that has a cross-platform filesystem on which to store your data then repartition and reformat the drive to the filesystem you want to use as one big drive and copy the data back over.

You don't mention the platform you want it in (Mac, since it's HFS+?) so outside of that advice, I don't know what to say. DD won't work if there's two different filesystems since you'll just image the first and second volumes, block by block, including their mixed filesystems, to disk images/copies on another drive.

Copy your files to a temporary storage area and repartition/reformat the disk and move the files back. If there are other particulars or requirements, please update your question.

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Edited, hope it makes more sense now. – pedromarce Feb 24 '11 at 14:12
up vote 0 down vote accepted

Ok, just for the record, it works without any problems.

First copy first disk into the new one...

DD if=/dev/sdb of=/dev/sdc

And then add second one skipping the volume of the first one.

DD if=/dev/sdb of=/dev/sdc seek=(BLOCKS OF DISK)

And I have consolidated my unusable disk into a new one.

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