Does built in Windows 7 backup perform differential (incremental) backups?

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I have win 7 scheduled to backup every Sunday, it's only looking at one of my drives at the moment and is backing up to an external HDD. It's a 1TB drive so should take quite a while to fill but the amount of time the backup takes makes me think its taking a fresh copy every time.

It's now 21:34 and I think backup started at about 19:30. It did a full backup earlier in the week of approx 200GB. Is it copying the whole lot again? Or is it just taking its time checking for differences?

G-.

Posted 2009-10-25T21:37:26.923

Reputation: 683

Answers

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Windows 7 Backup is a block based file backup.

This means each block in a file is examined and if a duplicate already exists on the last backup, and this is the important bit, even if from a different file, that block is not saved. Quite good :)

The first backup is always a full backup. The following backups will only save changed blocks. Disadvantage is you cannot manage your backups individually.

A Dwarf

Posted 2009-10-25T21:37:26.923

Reputation: 17 756

3So... If you deleted something prior to the last backup (therfore blcks have changed) does that file get removed from the backup image as well? – None – 2011-01-08T05:23:21.663

ah! Very clever. So the time delay is due to re-examining all the blocks. Do you have a link to some futher reading on this? – G-. – 2009-10-25T22:07:12.043

ermm.. will have to search for that. Been a while since I last read about it. Will add a comment with the information – A Dwarf – 2009-10-25T22:18:58.650

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Incremental here: http://social.technet.microsoft.com/Forums/en/windowsbackup/thread/c200e540-b36d-40c8-9957-690d447dbef9 Block based incremental here: http://social.technet.microsoft.com/Forums/en/w7itprogeneral/thread/457154de-2182-41d2-8e9d-738ead99440b

There's somewhere, on one of the developers blogs or something, a detailed explanation of the Backup features. That's where I remember reading about it the first time during the beta times. I just can't locate it right now. But those two links should be enough.

– A Dwarf – 2009-10-25T22:29:47.397

Anyone cares to comment on @user50272 comment? – Boris_yo – 2014-05-26T10:27:00.633