Mark Minasi's Tech Forum
Sign up Calendar Latest Topics

  Author   Comment  

Still Checking the Forum Out
Posts: 8
Reply with quote  #1 
We have been trying to figure out how Windows Server backup works, in particular, how it creates and stores its differentials. MS has little documentation in that regard.  What we seem to think is the following:

We do a first full backup to a USB on day 1.  Let's assume it's 100 gig.

Then on day 2 we do a 'fast' backup - which is a differential - all that has changed from day 1 - let's say it's 10 gig between new files created and others changed.

Then on day 3 we do another 'fast' backup - this one will have all that changed from the base on day 1.  Let's say on day 3 we did 20 gig of changes/adds.

We do not see any files representing the 10 and 20 gig additions on the backup media but we know WSB must have put it there as we can recover to day 1, 2 or 3.

So as it is not creating separate files our assumption is that it somehow adds the 30 gig to the original base image.  So the image file representing the backup is increasing in size - it is as if Windows was adding 'volumes' with each backup and somehow keeping track of where those volumes are via the catalog.

We would appreciate if someone were to go through our logic and comment - if someone actually has some MS material that would confirm or negate this that would be even better.  Thanks in advance for any feedback.


Avatar / Picture

New Friend (or an Old Friend who Built a New Account)
Posts: 30
Reply with quote  #2 
FWIW, I can't comment much on your logic because I do full "Bare Metal" backups, using two sets of HDDs - the latest goes in a safe onsite, the previous one to a SD Box at the bank - and they're swapped each week.  I then do daily "All Files Only" backups to locally stored HDD, maintaining the three most recent level.  This methodology goes all the way back to the 60's when we used tapes, because disks hadn't been invented yet.

In any case, I would emphasize, if you haven't done so, the use of the "Bare Metal" backup.  Just a standard full/differential backup can only be restored to an identical computer, whereas a Bare Metal backup can be universally restored to any computer; all you need is the new machine's drivers.  The logic behind this is because computers are ever-changing, and if your server crashes into a puddle of molten metal after a year or so, you'll likely not be able to obtain another identical machine, so the Bare Metal idea is a great CYA.

Hope this helps a little.

Capt. Dinosaur

Avatar / Picture

Associate Troublemaker Apprentice
Posts: 940
Reply with quote  #3 
A Windows Server backup is a form of incremental backup, where it has a full backup and then the changes since the last full backup.

MS Docs say it best. this is from Server 200
Automatic management of full and incremental backups. You no longer need to manage full and incremental backups. Instead, Windows Server Backup will, by default, create an incremental backup that behaves like a full backup. You can recover any item from a single backup, but the backup will only occupy space needed for an incremental backup. In addition, Windows Server Backup does not require user intervention to periodically delete older backups to free up disk space for newer backups—older backups are deleted automatically.

This is from Server 2008R2, but valid for 2012 + R2 I believe -

If you want to see it more visually, its not a MS Solution, but Veeam Endpoint protection will protect a physical computer to a USB or network share or virtual guest to a network share.
You can then look in the backup folders easier and see the file sizes, then look at the restores

Have you tried turning it off and walking away? The next person can fix it!

New to the forum? Read this
Previous Topic | Next Topic

Quick Navigation:

Easily create a Forum Website with Website Toolbox.