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Windows 7 Backup and Restore Problems

Posted on Nov 17, 2010 by Paul White

During my quest to upgrade my computer from my 4 disk SAS raid array to a 3 disk SSD raid array, I had a few learning experiences with the windows 7 backup and restore system.  Hopefully my tips will help others.

Windows 7 Backup and Restore is an awesome feature of the new OS. I have my system setup to backup my system drive every night.  Being that my system drive is a 4 SAS drive RAID 0 Array,  if any one drive goes out, everything is lost.  In recent days my system blue screened a few times on me and the result / cause was one of the drives on my RAID array had lost communication with the RAID Card.  After a reboot my RAID card told me that it was missing a member from the array.  So I logged into my raid card, and found that 1 of the drives was no longer initialized, and the other 3 drives had the incorrect size.  So I had to reinitialize my disks, and recreate my array.  After that I rebooted my machine with the Windows 7 install disk in my DVD-ROM drive.  Instead of reinstalling my OS, I was able to select the repair option and select my backup.  10 minutes later my system was back up and going just as I left it.  Keep in mind I was restoring a backup to the same disk that is was backed up from.

How to migrate your Windows 7 Installation to a new hard drive that is smaller

There is a catch with Windows 7 Backup.  The disk that you restore the backup to must be bigger or equal to the disk you did the backup from. In my case I backed up a 588 GB RAID Array.  When you are using windows Backup you are not just backing up the files. You are backing up the entire Partition.  Even if you are only using 100 GB of a 588 GB RAID array, windows will still backup the entire partition.  Then when you go to restore the partition you must restore it to a disk or array that is 588 GB or larger.

In my case I was wanting to move from my 4 Fujitsu 147 GB SAS drive RAID 0 array to 3 OCZ 60 GB Vertex 2 SSD RAID 0 array.  So I was trying to migrate from a cumulative 588 GB array to a 180 GB array.  Naturally I had a learning experience with this.  When I tried to get windows to restore my data to this smaller array it gave me an error.  After some research I discovered the issue with the partition sizes. 

When you run Windows Backup its not just copying your data. Its copying your partition information as well.  So if you do a windows backup on a 120 GB drive, when you use Windows Restore it will erase the destination disk, and setup a 120 GB partition on the disk regardless of the hard drive's physical size.  Of course if your disk is only 80GB its going to give you an error.  It doesn't matter if you only have 20 GB of data on a 200 GB disk,  Windows Restore is still going to try to create a 120 GB partition. 

So if you were in my position and trying to migrate your boot drive to a much smaller Logical drive, you will need to shrink your partition first.

Shrinking your Partition

Lets say you have a 200 GB hard drive setup with a 200 GB partition storing 20 GB of data.  When you ask Windows 7 to shrink the partition it will determine how much unused data is at the end of your partition.  Keep in mind data can often be fragmented and stored all over your parition.  If you have some files at the end of your partition, trying to shrink a partition might only free up a few MB.  So before you shrink your partition you need to make sure all your data is at the front of the partition.  To do this you run defrag.  But defrag will not move system files like your page file and your hibernation file which can each be several GB in size

The steps to shrink your partition to the max are this.

Disable Windows Page File ( note be sure you have at least 2 GB of memory before you do this )
Disable Hibernation
Reboot your computer
Check your C drive to make sure the hibernation file is gone ( might have to enable view hidden files and folders under folder options ), if its not delete it.
Completely Defrag your hard drive ( recommend using defraggler )
When defraggler finishes make sure all the data is at the top of the drive.
Now you are ready to shrink your partition
Under computer management right click on the drive and click on shrink partition.
Don't shrink the file to the max.  make sure you have a few free GB left.
After its done, run Windows Backup to backup the new smaller partition.
Now you are ready to restore this partition to a smaller disk.
After you have restored the partition to a smaller disk, you can expand the partition to the maximum size of the physical drive.

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