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Old 12-04-2007, 04:43 PM   #1
pentalive
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Quick DD unequal size drive question


dd if={40gb hard drive} of={120gb hard drive}

What happens?

I suppose the 120gb hd looks like a 40gb hard drive afterward. If so is there any way to get back the lost disk space?

(this in a more recent distro than RedHat 7.3)

Last edited by pentalive; 12-04-2007 at 04:45 PM. Reason: clarifacation
 
Old 12-04-2007, 05:00 PM   #2
jailbait
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Quote:
Originally Posted by pentalive View Post
dd if={40gb hard drive} of={120gb hard drive}

What happens?

I suppose the 120gb hd looks like a 40gb hard drive afterward. If so is there any way to get back the lost disk space?

(this in a more recent distro than RedHat 7.3)
You might be able to make the lost space usable by changing the partition table.

---------------------
Steve Stites
 
Old 12-04-2007, 05:54 PM   #3
pentalive
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Originally Posted by jailbait View Post
You might be able to make the lost space usable by changing the partition table.

---------------------
Steve Stites
Is there a linux tool that will grovel through the disk drive and create a partition table?
 
Old 12-04-2007, 06:07 PM   #4
pixellany
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dd copies everything literally.......

If you copy the whole drive (if=/dev/hda), then it copies the MBR, partition tables, and all partitions. Going from 40 to 120, you will wind up with an image of your 40GB drive at the front of the 120. I assume you can then resize and/or create new partitions to fill the excess space.

When you clone just a partition (if=/dev/hdaX), then that's all you get. I assume that you have to copy to a target partition which is at least big enough.
 
Old 12-04-2007, 06:14 PM   #5
chadl
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fdisk can increase the size of the partition, but you need to know exactly how big the disk is to be able to tell it (because it only knows what is on the partition table, that is from the small disk). It is very easy to screw everything up beyond repair while doing this. Read the man page for more info.
After that is done resize2fs (or the tool for your fs type) can increase the size of the file system to match that of the new partition.
 
Old 12-04-2007, 06:34 PM   #6
syg00
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Nuts.
Create new partitions on the big disk, and copy ("dd" if you insist) each partition in turn.
 
Old 06-30-2009, 11:31 AM   #7
boutch55555
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The easy way

Since this is the only thread I found on the dd resizing, I will add my solution :
Tested with ext2 on ubuntu 8.10 with 4gb (almost full) sd card to 8gb sdhc card.
I simply opened gparted, reduced the size of the partition of about 10mb (gparted was saying I had a 7.x gb partition almost full), and then expanded it to full size again (gparted now says I got a 7.x gb partition with 4gb free, df tells me the same). Took 3 minutes

hope this helps
 
Old 06-30-2009, 02:09 PM   #8
pentalive
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That's it

Thanks everyone for your answers.

Pentalive.
 
Old 04-30-2010, 12:49 AM   #9
myjess
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Quote:
Originally Posted by boutch55555 View Post
Since this is the only thread I found on the dd resizing, I will add my solution :
Tested with ext2 on ubuntu 8.10 with 4gb (almost full) sd card to 8gb sdhc card.
I simply opened gparted, reduced the size of the partition of about 10mb (gparted was saying I had a 7.x gb partition almost full), and then expanded it to full size again (gparted now says I got a 7.x gb partition with 4gb free, df tells me the same). Took 3 minutes

hope this helps
Now that is just lovely. Exactly what I needed when booted off the ubuntu live cd and installed gparted to fix a dd copy.
It's 6 months since since thread but I just gotta thank you.
 
  


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