Increasing size of RAID1 on a Win7 system

Increasing size of RAID1 system drive on a Windows7 machine using a hardware raid (Intel Rapid Storage Technology) built by a Microsoft Deployment Toolkit (MDT) deployment

A stumbling block is the BDEDrive which is placed immediately after the system drive by the MDT tool; ideally this partition should be the first on the drive to save problems like this.

The BDEDrive is used by BitLocker, if you are using BitLocker then there are some additional steps to follow which are outlined at the end of this article. If you are not using BitLocker then you can delete the BDE drive as outlined in the main body of the article,

You can enter the Intel® Rapid Storage Technology option ROM by pressing Ctrl and i when prompted during POST.

Increase size of RAID1

1. Turn off the system and remove one of the hard drives.
2. Replace it with one of the large hard drives, ideally port 1 leaving the smaller drive on port 0
3. Turn on the machine and ensure the RAID is set to rebuild in the diagnostic screen during POST
4. Once booted into windows, use the Intel® Rapid Storage Technology user interface to monitor rebuild progress
5. Once rebuilt, turn off the system and change the remaining small disk, ideally swap the large drive from port 1 to port 0 replacing the small drive and add the new large drive to port 1
6. Turn on the machine and ensure the RAID is set to rebuild in the diagnostic screen during POST
7. Once booted into windows, use the Intel® Rapid Storage Technology user interface to monitor rebuild progress

Deleting the BDEDrive

Before the BDEDrive can be deleted the system needs to be configured using BCDboot to replace the boot mechanism used by BDEDrive whether or not BitLocker has been enabled or not.
 BCDboot copies a small set of boot-environment files from the installed Windows image to the system partition. Next, BCDboot creates a Boot Configuration Data (BCD) store on the system partition that instructs the computer to boot to the Windows partition.

Use BCDboot tool from the command line

• bcdboot c:\windows /s c:

You now need to make the c: active using diskpart tool.

• diskpart
• select disk 0
• select part 0
• active

Then you can delete the BDEdrive partition either using the disk management console or using diskpart.

• diskpart
• select disk 0
• select part 1
• delete partition

Reboot into windows, windows will see the smaller drive size unitl the RAID is reconfigured, using the Intel RST tool to increase the size of the existing RAID array.

Once the RAID array has been increased; progress of which can be monitored in the Intel RST tool.

Reboot into windows and using the disk management snap in increase the size of the C: drive

Do a final reboot of windows to ensure all changes have been completed successfully

What to do if you need to use BitLocker

1. Temporarily disable BitLocker and decrypt the C: drive. Applying the chkdisk /f as required until all error are fixed.
2. Follow the instructions in the main body of the article until you expand the C: drive, if you need to use BitLocker you will need to leave space at the end of the drive for the partition to be created; leave at least 300MB, preferably around 500MB of space when expanding the C: drive
3. Once the system has completed its final reboot and confirmed the new size of the C: drive
4. Re-enable BitLocker which will create a new BDEDrive partition and ask you to save the recovery key.