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I have a 500G HDD that came with my Mac. About 30 GB are currently used.

I want to replace the 500G HDD with a 256G solid state one. I'm running HDD Raw Copy to do this.

It didn't complain about the fact that the destination is much smaller than the source. It's started the copy.

I'm not sure this will work! How does an HDD work? Will all the vital data be in the "early" sectors? What if there is a piece of data in a far off sector in a far away platter?

This site recommends that I:

  • Place your original drive in an external enclosure.

  • If running OS X 10.7 or later, boot to the recovery partition on your original drive by holding down Command-R and starting up.

  • Use Disk Utility to Restore to your new drive.

  • Restart or Boot your Mac to the new drive.

Would that have been a better route to take, considering the destination drive is much smaller than the source?

share|improve this question
Assuming that Macs work like other computers, which is a fair-ish assumption, you probably don't want to copy the whole hard drive. Copying the whole drive would copying the fact that the partition is assumed to be X bytes big, and you don't want that. Also, if you just try to copy a hard drive's image, either computer may legally use later parts of the partition. First, defrag the drive, to try to get data towards the beginning. I understand that defragging is not common procedure with some filesystem types. Then, resize the partition. Try to use a tool to just copy the partition. – TOOGAM Jan 23 '15 at 17:14
up vote 1 down vote accepted

I can't speak for Raw Copy from experience, but looking at the site it appears that it will happily copy your data over, without warning you that the system will be useless :/

The instructions you posted above are exactly what I recommend, and will cause you the least amount of grief; the concern I have is that when you do a disk dump from one drive to another, it doesn't just copy your files; it copies what the drive thinks it looks like. The file allocation table will assume that it lives on a 500gig drive, because that is how it was partitioned. The moment it tried to read past the physical location of 256gigs, there just wont be a sector to address. Would be like half the planet falling off, but you have no way to know till you're in an airplane on the way to Japan.

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You were right, the copy actually "failed" 1/2 way through (after 256 GB had been written..) then the mac refused to book (folder with a question mark) when I actually tried it. – bobobobo Feb 6 '13 at 4:38
Note you "can't use the startup disk as a restore source", so I had to boot from the Recovery Utility – bobobobo Feb 6 '13 at 5:09

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