Creating a new differential backup after a restore

Mooly said:

Possibly yes......

Although creating a new incremental or differential based on a restored image will work, you might be surprised just how big that new image is. Although outwardly nothing has changed, the reality could be that pretty much everything has......

An analogy. You are making an image of all the books in the local library. You restore that image and everything is put back exactly where it was... almost. Now suppose each row of restored books was a little to the left or right of where they were before. It makes no difference to the user, but the program imaging the books thinks every one is now different and so creates a new differential or incremental image to reflect that. The result is that the differential or incremental image can be almost as big as starting a new full sequence off.

Differentials are an order of magnitude smaller - the OS hardly changes in size.

You should always do a full image backup after a build upgrade which is when most files change. I do not think diffs can handle a build upgrade but never tried it.

Unless you are writing GBs of data a day to C drive, differentials are normally quite small.

Your analogy is incorrect as Macrium is far more clever than that. Files do not get restored in same location - it uses smart sector copying.

Mooly said:

I was basing my comments on experience with Acronis in years gone by. Personally, I would never continue backing up a restored image to a pre-existing chain, whether incremental or differential.

Although I agree that you should always do a new full image after a major upgrade, there is no technical reason why a differential or incremental would fail... it should after all correctly identify the sectors that have changed and perform the backup accordingly.

Differentials are not chained, only incrementals.