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Windows 7 RC Backup - Is it Incremental?

    Question

  • I have some basic questions regarding Windows 7 RC backup:

    I have been creating regular backups for the last 3 weeks and the backup size does not seem to be increasing much. My impression is that the backup is incremental, only adding files that have changed or been added. If I choose "Manage Windows Backup disk space, it shows only one entry: "Backup Period: 5/17/2009 - 6/1/2009 49.0 GB." I can only delete ALL of the backups, but not individual backups. I am frustrated that I cannot get specific information from the backup/restore utility that tells me what is really there. How do I get multiple full backups that aren't modified / replaced? Does anyone know how backup really works - is it always incremental ?

    More info:
    I have about 66 GB of files on all my hard drives according to Explorer and I have chosen to back up all files on all my hard drives. Yet the backup says it is only 49 GB. But on the main backup/restore screen, it says my "Backup Size is 65.9 GB." I am guessing that 65.9 GB includes the system image that I also have included with the backup. But nothing is spelled out. With backup I want to be 100% sure how it works. How do I tell what my backups actually contain - is it merged into one big backup?

    Another question: Do I really need a repair disc? If I have the original Windows install disc, is this enough?

    Lastly, What are other people using for backup that gives better control and is very reliable?

    Thanks for your help. - Michael
    Wednesday, June 03, 2009 3:38 AM

Answers

  • It's a block based file backup. Each block in a file is examined. If a duplicate already exists, even from a different file, it is not saved. After the first backup only the delta or the changed blocks are saved in the next backup. It works almost the same as Vista and Server 2008. This is a very simplified overview but in a nutshell that's how it works. It's quite versatile and robust. Because of how it works it may not fit every situation but it does fit most.


    Kerry Brown MS-MVP - Windows Desktop Experience
    • Marked as answer by Michael- Wednesday, June 03, 2009 1:13 PM
    Wednesday, June 03, 2009 5:13 AM

All replies

  • Michael -

    I can only answer some of your questions...

    Some files may NOT be backed up - namely the pagefile.sys or the hiberfil.sys. Those files can eat up a fairly good chunk of disk space and may account for the smaller size of the backup. Those files don't really need to be backed up - Windows will generate them as needed whenever a restored backup is fired up for the first time and aren't used for any sort of long term storage. The hiberfil.sys file only contains an image of what's in the active RAM at the time when you're putting the computer to sleep. The contents of Pagefile.sys are likewise transitory.  

    In addition, there is likely some compression being applied to those files.

    The Repair disc is designed to allow you to boot from the CD so you can restore from the backed up System Image disc(s). So, it depends. Do you want to reinstall Windows and then restore the backup or just go straight to the matter and restore the backup?

    I don't personally use the Windows backup - so I can't tell you much more about it.
    Wednesday, June 03, 2009 4:02 AM
  • Lastly, What are other people using for backup that gives better control and is very reliable?

    Thanks for your help. - Michael

    I like the company "Acronis" and I've used "true image echo workstation" in the past, and it was reliable. Any backup program that does not need an OS to restore the OS is nice.
       But once during beta I decided to rearrange my partitions and restore/repair using microsoft's software. The repair disk was useless and the restore restored but Windows was no longer genuine, and would not let me run anything. Subsequently a knowledge base article pointed out to me that I was not allowed to rearrange partitions and hope to restore.
    -------
    If you're feeling brave and etc, using your best backup solution, wipe your disk, restore, or run the repair, it's the only way to know, but it's discouraging usually. Acronis has helped me in the past, but I defer to smarter braver ones (MVP's & answerers) to tell you about backups for windows 7.
    Wednesday, June 03, 2009 5:10 AM
  • It's a block based file backup. Each block in a file is examined. If a duplicate already exists, even from a different file, it is not saved. After the first backup only the delta or the changed blocks are saved in the next backup. It works almost the same as Vista and Server 2008. This is a very simplified overview but in a nutshell that's how it works. It's quite versatile and robust. Because of how it works it may not fit every situation but it does fit most.


    Kerry Brown MS-MVP - Windows Desktop Experience
    • Marked as answer by Michael- Wednesday, June 03, 2009 1:13 PM
    Wednesday, June 03, 2009 5:13 AM
  • Thank you all for you insights. Kerry, you've answered the big picture question for me. I had never heard of block based file backup and a Google search shows this information is not widely known about Windows 7. I feel I can now better make decisions about what to use for my backups. Thanks.
    Wednesday, June 03, 2009 1:12 PM
  • Is there somewhere a fairly detailed paper on Windows7 and Server2008 backups? They seem fairly similar yet Win7 keeps the system image as a separate file at the root of the drive. This is rather irritating. Also restore should be able to restore from backup sets that have been saved to other folders and should be more clear as to why replacing a backup set fails to restore with a media id failure when all you have to do is basically say these are another set of backups yet they still have to be in the root. Fiarly nice overall but would be better if how all this worked was better documented somewhere rather than the extremely light documentation coverage given to an extremely important area. Anyhow, if there a more detailed paper on both of these new system backups, I'd love to have a reference so that I can learn more about how they are designed and work in more detail Thanks, Dave
    Tuesday, October 27, 2009 7:44 AM
  • I created an initial file using backup which was larger than half the disc size of my backup drive, I scheduled a second run 1 week later.As I only added a megabyte of data to the files during the week I assumed that only the extra megabyte of data would be addd to the backup files and I would still have plenty of room on the drive. However when I have come to check the backup this morning (I left it running overnight) almost all the free space on the backup driveis full with only three quarters of the backup complete. Do you need  to specify you want an incremental backup rather than all the files or am I missing something?

    Thanks .... Tim
    Monday, November 09, 2009 8:48 AM
  • I have an exact copy of tim_woodäs case. I cannot make a 2:nd backup, since the 1st backup (lot of photos) occupy 350 GB of the total 600 G; in my opninion the 2:nd backup consisting of new and changed files should not occupy more than a few GB - but it fills up the 250 G and reports low   disk capacity. and stops. I own this computer (HPE 035)since December but could not make any succesful backup  yet!!!
    Monday, January 11, 2010 3:40 PM
  • Do you have more than one or two drives in your system? If so make sure backup is not trying to add that to the backups as well (select "let me choose"). Photos won't compress much but I agree that if you only added 1G you should at most get a another gig added to the existing backup. If you include a system image then that will potentially add some additional backup space for any system files that changed besides just your image data but should not be what you are describing. Let us know what you figure out on this...
    Monday, January 11, 2010 6:41 PM
  • Did you ever figure out this problem? I seem to have the same problem a full year later. My second backup is over 500 gigs and there is no way I added over 500 gigs from the first month when I did a 950GB backup. I'm backing up my 80GB C drive, and two 750gb secondary drives, neither of which are full. The 950GB is about the right amount of date for all 3 drives... so why is my second backup 500+gigs when I may have only added 10gigs.

    Sal

    Monday, January 17, 2011 5:08 PM
  • Perhaps something like this?

     

    http://support.microsoft.com/kb/981470

     

     

    Wednesday, September 07, 2011 5:38 PM