# Solved: Disk Cloning vs Disk Imaging?



## DexterDave (May 10, 2011)

Hi All

What exactly is the difference between Disk Cloning and Disk imaging? I am using Macrium Reflect to make a backup of my Windows C drive, but I'm not sure which one to use.

Thanks


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## bbearren (Jul 14, 2006)

"Disk Cloning" usually refers to making a bit-for-bit copy of one disk and transferring that copy bit-for-bit to another disk, as in replacing an old and failing drive with a new drive; usually.

"Drive Imaging" usually refers to making a bit-for-bit copy of a disk/partition, compressing that copy into an "Image File", and storing that compressed drive image as a backup in the event of future need.

I use drive imaging as my preferred method of backup.


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## DexterDave (May 10, 2011)

Thank You, I appreciate. Should I image my drive C (Windows Drive), will it backup all my files (such as images, movies etc) or will it just backup my system files an programs installed on that drive?


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## Elvandil (Aug 1, 2003)

You should image. Cloning uses a whole drive. The image will include absolutely everything on the drive (except the page file and a few other unneeded things), programs, Windows, personal files, settings, and all.

Make the boot disk so you can use it to restore the image to a new drive when your C: drive fails.


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## bbearren (Jul 14, 2006)

If you have more than one partition, for archival purposes it would be a good idea to make an image of each partition. If yours is an OEM installation, there is probably also a smaller "Recovery" partition. In order to completely restore everything from your original drive, should it fail, to a new drive, it would require an image of every partition that is currently on that OEM drive.

Also, your drive image files should be stored on a separate drive, such as an external USB or eSATA drive. If you store your images of your partitions on the same drive the partitions are on, you'll likely lose everything should that drive fail.

If you store your personal data on a separate partition from the system drive (such as a D: drive/partition), you should make regular images of that partition, as well.


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## DexterDave (May 10, 2011)

@Elvandil and bbearren - cool, thanks a lot! Really appreciate your advice. I do backup that partition image on an external. Good thing you tell me that it backs up everything, so now I don't need to backup my movies, series and photos manually everytime... Thanks Again


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## DexterDave (May 10, 2011)

To make the image file bootable, what format should it be in (the bootable file), and what file types are bootable apart from ISO files?


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## fairnooks (Oct 1, 2007)

The only problem with making an image all the time is if you have a lot of data (movies, series and photos) and it changes fairly often so that you should back up fairly often, is that it will take a long time each time to make the image, and they are going to take up a lot of room when you've backed up a few versions. If that's not an issue then its a good solution.

An image file itself will not be bootable, it will be in the proprietary format associated with the image program. It is restored using a boot disc or possibly a bootable thumb drive you make separately, created when you first install the image software. Also, depending on the image software you use, there is often a method to "mount" the image file as if it were another drive, so that you might retrieve or access data stored in that image without having to restore the whole image to get at any of the data.


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## Elvandil (Aug 1, 2003)

Images are not bootable. You recover the image using the boot CD. ISO's are not bootable, either (though they can be booted using GRUB, only if they are bootable ISO's). Only bootable (with a boot-sector and files) CD's and DVD's are bootable (as well as bootable USB devices, of course).

Once you have a full backup image, you can make an incremental one from time to time. They are much smaller because they only back up the differences from the original and last incremental. They are faster, too, so that you have no reason not to make them often.When restoring, you then have multiple dates to choose from, like System Restore. Occasionally, you can start over and make a new, full one. Some imagers have built-in schedulers that you can use that automatically delete the oldest images as new ones are added.

You need to keep all the incremental backups in order for the last one to be restorable. But with a differential backup, again, only the differences from the original are backed up, but you only need to keep the last differential to use it for a restore. That can save space, but differentials are larger and you have fewer dates to choose from when restoring. I have close to 20 images all the way from a month ago in a space of 250 GB's for a partition that is 125 GB's in size. So you can fit a lot of them in a relatively small space.

You can mount an image in Macrium to access it as a drive if you want to just recover files or folders (but in Windows 7, you already have several backups of all your files stored as shadow copies on your hard drive that you can access any time).


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## fairnooks (Oct 1, 2007)

I see I think, so at the point of incremental updating the image it is similar to updating a zip file, wherein the file is unzipped, added to/changed or used as the basis for the incremental and then zipped up again? Or is there a separate index for comparative reference and is the incremental always an additional file created alongside the original image?

Either way, seems a bit more clunky and a trifle harder to access than a one to one synchronized data backup of changes but I guess I see nothing fundamentally wrong with it. I suppose its mandatory to verify each time and hope that that is foolproof or maybe mount the image each time and spot check?

I guess I have a trust issue with anything that is even slightly obscured repeatedly. : )

Edit: Maybe I confused myself even more cuz now differentials are in the discussion too.


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## Elvandil (Aug 1, 2003)

The full image remains untouched. The incremental is a smaller file alongside. Validation allows either the full package or just the most recent incremental. When restoring, any file chosen among the group will offer all the rest of them as alternatives, so you can choose the original full, or any of the incrementals along the way.

I do a validation only once a month. If the log states that the backup succeeded, that is generally the case. Of course, a validation may be done more often at critical times if desired.

If you mount the last incremental, for example, you will see the image of the entire system in the state that it was in at the time the incremental was created. It basically loads the full original with the changes shown in the last incremental. So to the user, it appears the same as if a full backup had been done on that date. It saves backing up everything more than once.

In Acronis Backup & Recovery, I use their built-in Grandfather-Father-Son schedule, slightly altered. I don't completely understand its logic, and it creates mostly incrementals with an occasional differential, with new, monthly fulls. But I'm sure there is logic to it since I have plenty of backups going back a month, not much space is being used, and older images get deleted automatically. I've restored a few of them without any problems, even to different hardware with Universal Restore.

Many people only make full backups. I'm not sure if it because they don't trust incrementals, or just don't understand them. But as you say, fulls take a long time, and people will not keep updated backups that take hours every day. Incrementals, mine taking 5-10 minutes, 1-4 GB's, on average, made often, are quick and do the job. Run on low priority, I hardly notice that it is even happening.


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## fairnooks (Oct 1, 2007)

Ok, that helps, so say one makes a daily incremental, each one is based off the original full image, not off the original full image AND each incremental between the full and the most recent incremental, so if one wanted to restore the most recent image, it would only include the original image and the most recent incremental, not all the incrementals up to that point.(?)

I personally never got into them because I share my data with many different workstations and while I use one of the workstations as the main source because its faster to access than my NAS drive, the data is still system independent. In fact the source system has been down for a few days with a PS issue and I just switched over full time to the NAS drive for now. Seems like imaging only doesn't quite have the flexibility needed for multi-system/device households/networks.


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## Elvandil (Aug 1, 2003)

No, unfortunately, all incrementals need to be there to restore the last one. But differentials are as you say and you only need the full and the last one to restore. Differentials record the changes since the full, and incrementals store the changes since the last incremental.

Acronis has many other forms of tools for servers and corporations aside from what it has for end-users. It may not be for everyone, but it's a definite boon to home users, especially those who don't know what to back up, or don't want to start from scratch. Acronis can FTP images to another location as well.

Having a clone and a backup system that only synchronized would work well, too, and you'd always have a bootable backup at the ready. All better than RAID where errors are backed up immediately and you end up with 2 dead drives instead of 1.


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## DexterDave (May 10, 2011)

thank you very much! appreciated


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## Elvandil (Aug 1, 2003)

I'm not really pushing Acronis. It just happens to be what I've used the most. Healthy competition has made most of the major guys offer similar options. I like Paragon a lot, too. And Macrium is an Acronis clone, almost.


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