Can I clone a large hard drive (with little data on it) to a smaller hard drive (with no data on it) with “dd”? Is there a better way?

Question

I recently got a new desktop, and two hard drives to go with it: a 128GB solid state drive, and a 750GB hybrid drive.

I installed Windows to the hybrid drive, but have come to realize that it would be worth having OS's on the SSD and media on the HDD.

I'm hoping this is as simple as cloning the HDD to the SSD, then wiping the HDD.

My plan would be to boot to some Linux Live CD, mount the drives, and run "dd if=/dev/sda of=/dev/sdb"

Answer 1

Use Microsoft's free imaging tool ImageX. Download it with Windows ADT. You'll need to do some work via commandline, but you'll be able to build a WinPE bootdisc and capture the image.

From WinPE:

imagex /capture c: d:\imaging\data.wim "Drive D" /verify

Then to apply:

imagex /apply c: d:\imaging\data.wim 2

see below for more info and examples:

http://technet.microsoft.com/en-us/library/cc749447(v=ws.10).aspx

Answer 2

Cloning between drives directly will clone the partition table. This is problematic because the new drive will appear as having a partition that is larger than the drive in this case. Cloning raw data is even more problematic because there is no guarantee that the files are condensed on the first 128 gigabytes of the larger drive.

The safest thing to to is to partition the new drive with a dedicated tool instead of cloning partition tables and after that transfer all files by copying files as one would casually or by means of an image.

When you work with filesystems native to linux, the simplest solution is to format the target drive according to needs and rsync whole file systems over to the new partitions. The final step is to copy the MBR (first 512 bytes of a hard drive).

With NTFS, there is ntfsclone from the ntfs-3g package that could be used to make snapshots. Beware though, that you will likely have problems booting after restoring an image to a new partition. The manual page of ntfsclone explains why.

The easiest way to make a Windows installation bootable again after cloning is to run the installation and selecting the "Repair Windows" procedure. Although on most simple (one hdd - one partition) setups, cloning the MBR with dd should do the trick.