A cloned external hard drive to replace an internal HDD

Yes to both of your A and B questions. I'm not positive about the Western Digital version of Acronis, but the standard Acronis and Macrium Reflect Free do it.

Windows can be cranky about being run from an external. I'd try to avoid that.

You could make a "clone" of your internal to some other drive and then simply replace the internal with the other drive if the internal failed.

But I wouldn't do that either. That's cloning. It can work, but I'd guess the experience around here is that it doesn't work as well as imaging.

And a clone quickly becomes out of date due to continued Windows Updates and continued new programs you install, configuration changes you make, etc. You'd have to make new clones and hope each new one works.

Cloning and imaging are noticeably different processes, but can be used for similar purposes.

Cloning typically clones the entire drive. Imaging typically images only the chosen partitions. C, D, and E. C and E. D and E. C only. Whatever partitions you specifically choose.

Imaging just makes a file that you store on some other drive, just like any file. If disaster strikes, you go through a formal "restore" of the image file to an internal drive, and that restoration makes the drive bootable again, in the same state it was on the date the image file was made.

Image files can be made at will, might take 10 minutes to an hour at most on the average machine. You might make one a week or one a month, whatever suits you.

Cloning makes an exact copy of drive A onto some other drive B. If it works, the B drive is usable right then, without a "restore". You can do an immediate swap. Remove drive A and replace it with drive B.


Imaging requires a restore, but does not tie up a drive. You don't "swap". You restore the image file. Image files occupy perhaps 1/2 the occupied space of the imaged partition.

There will always be some doubt in your mind about whether the restore will work. You can't know for 100% certainty. But Macrium is probably 98 or 99% reliable.

You could do a full test of a restore after swapping in a new internal drive. You can also make a test image of a data only partition and restore that.

You've got a lot more nerve than I do if you would try to restore an image to a known good and working system. You're taking a chance of over-writing a good system with a failed restore that won't work.

At a minimum, you should certainly test your rescue media and make sure it will boot your PC. And you should "pretend" you had a drive failure and walk through the first few steps of an image restore---stopping before the final step where the restore would actually kick off. You should do this because you need to know what menu choices you will be faced with and what you would actually do when the heat is on and you are in a bad jam.

You are probably safe if you make two or more full images of your OS and data partitions onto at least one if not two external HDs. At home, I have two usb external 1TB HDs for each computer; I average close to weekly or bi-monthly backups; often keeping at least 2-3 OS [C] partition backups and one data partition [D] backup. Fireberd [sevenforums] does full images of the entire HD, I've recently adopted that idea, added it to my current routine.

sunsetlover said:

If my purpose is to upgrade or replace an internal drive, then cloning is the way to go.

I don't believe this is correct. A full system image using a reliable program like Macrium should be fine. I have carried out this procedure on a number of occasions. You can get a replacement HDD and try it out.

see comments in bold

sunsetlover said:

Thank you both.

If my purpose is to upgrade or replace an internal drive, then cloning is the way to go. Of course I could do both cloning and imaging and keep and update an image as back up.

I would say imaging rather than cloning. Either can work. It seems to me that imaging is less likely to be problematic, but try cloning. If it fails, try imaging.

but an image restore will require a bootable media, correct?

Imaging typically requires bootable media, but I think the current version of Macrium lets you boot directly into the Macrium interface and do a restore---but this would only be an option if your hard drive was still functioning. I haven't checked that functionality and still just use bootable media--either DVD or USB stick.


About the specifics of cloning, does Macrium or Acronis take any external target drive and partition and format it according to the source drive, or I can specify, correct? ie. basically the target drive only needs to be initialized?

As far as I know, the target drive can be in any state when you begin the clone---it just needs to be in good operational order--not defective. And large enough. I think the formatting is done by the cloning application. If the source is 500 GB and the target is 1 TB, I'm not sure if you end up with 500 GB in partitions and 500 GB unallocated--in which case you could add the unallocated to the partitions after the fact. Or you might end up with all 1 TB in partitions, where the cloning app automatically makes the partitions proportionally larger.

I'm not sure you can specify partition sizes before or during the clone--you may have to do it all after the fact.

I've never done a clone personally.

All the comments in bold does not justify the statement:
"If my purpose is to upgrade or replace an internal drive, then cloning is the way to go."
I don't agree with the statement as a generalization but accept the OPs preference of course.

Other people read these posts and all I'm doing is refuting the comment as a generalization.