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Windows 7: Migrating from RAID to AHCI, Win 7

18 Jul 2012   #1

Win 7 Ultimate 64
Migrating from RAID to AHCI, Win 7

The conclusions are :
- The raid field cannot be migrated from RAID mode to AHCI mode directly; needs to be recreated
- AHCI mode decreased the booting time by 20s
- EasyBCD is not almighty; if it's not working, try Visual BCD Editor
- there are still nice people out there willing to help

Current setup: 2x HDD in raid 0 (stripping, 4TB ) and 1 SSD (system, 120GB) ; The RAID mode is selected in BIOS. Mainboard Gigabyte GA-880GM-UD2H. Windows 7 Ultimate 64, NTFS

It was built 2 years ago with the system installed over the two disks in raid 0. Recently I bought a SSD and migrated Windows onto it. I have read that Gigabyte with AMD controllers have performance issues in RAID mode and that it's recommended to use the AHCI mode.

Is it possible to migrate to AHCI mode without loosing the data (for my setup)? Is it worth it? My guess is that since Windows are on one disk it should be possible to boot them and run the two disks in a (software?) RAID.

In addition the BCD was not transferred correctly to the SSD (it is still on the raid disks) and when I change the mode to AHCI I get the 'missing system' message. There is some problem with it to be migrated to the SSD (seems like access rights) and before I play with it more, I would like to know if it's worth it. At the moment, the system is working

Thanks for any advice

My System SpecsSystem Spec
18 Jul 2012   #2
Microsoft MVP


Please post back a screenshot of your maximized Disk Management drive map and listings:

1. Type Disk Management in Start Search box.
2. Open Disk Mgmt. window and maximize it.
3. Type Snipping Tool in Start Search box.
4. Open Snipping Tool, choose Rectangular Snip, draw a box around full map and all listings.
5, Save Snip, attach using paper clip in Reply Box.

Tell us what is on each partition.

Check also the BIOS settings to see if you have a RAID controller pop-up when you first boot the computer which must be disabled in additon to the setting change to AHCI.

You'll likely have to move your data off the RAID first to unRAID it.
My System SpecsSystem Spec
18 Jul 2012   #3

Win 7 Ultimate 64

Thanks for the quick response.

Basically there are three disk. Disk 1 and 2 are a raid field (2 physical disks, raid 0).
Disk 1 - 235GB:
100MB system reserved, hidden partition,
200GB previous Win 7 partition, now hidden and there are no issues with the SSD will be deleted
35GB - Secondary/emergency windows installation; I guess this one will be inaccessible in AHCI mode

Disk 2 - 3.6TB, GPT:
115MB - system created
3.5TB - data
172GB - data

Disk 3 - 120GB, SSD
100MB - system reserved
104GB - System disk - Win 7 64
10GB - reserved for additional OS

I have attached a sceenshot


Attached Thumbnails
Migrating from RAID to AHCI, Win 7-screenshot.png  
My System SpecsSystem Spec

18 Jul 2012   #4
Microsoft MVP


The reason I asked to see a Disk Mgmt screenshot is that other managers show the System Active boot labels differently. Judging by the screenshot of whatever manager you posted SSD is booting from C and SysReserved isn't even Active on it. But it could be inaccurate and needs to be seen from Disk Mgmt.

If you're saying that when you disconnect the RAID the SSD won't boot then you need to back up data from RAID to do that, mark System Reserved on SSD Active, then run Startup Repair - Run 3 Separate Times to write the System Boot files to System Reserved, until it boots and shows the System Active flags on it, with Boot flag on C as seen from Disk Mgmt. Partition - Mark as Active

I would offload the files from the RAID, unRAID it in RAID controller if necessary, change to AHCI mode to test SSD performance, move SSD to DISK0 to avoid future problems (keeping it set to boot first in BIOS setup) then plug in the other HD's to use for data, wipe them if they interfere with Diskpart Clean Command to partiton and use for data and image storage.
My System SpecsSystem Spec
18 Jul 2012   #5

Win 7 Ultimate 64

screenshot from disk management.

Yes, I had difficulties in moving the BCD to the 100MB partition (using Easy BCD). When running CMD commands, I had some strange 'access denied' messages - I think this might be that as the BCD was created (or tempered) from 3 independent windows installation, the user ID will be different...

Would you expect a benefit (probably speed) from changing to AHCI mode? I will repair the bcd as suggested, once I get the time.

I have no storage to unload the data from the raid, so I try to connect the RAID disks onAce the system is up and running from the SSD in HCI mode and see if the data are recognised. If not, I will have to revert to raid mode. Anyway this should deal with the BCD mystery

thank you for your time

Attached Thumbnails
Migrating from RAID to AHCI, Win 7-screenshot2.png  
My System SpecsSystem Spec
18 Jul 2012   #6
Microsoft MVP


Moving the boot files with EasyBCD does not complete the job since the WINRe link is not rewritten to F8 Advanced Boot options, so running the three Repairs is more comprehensive and tests many other functions at the same time.

If the performance of the SSD is not compromised by RAID then I wouldn't change it if you don't have a way to offload the files - athough files should always be backed up anyway.

When you get an external or other backup method such as Skydrive which offer 7gb free with each Windows Live ID, then you can experiment to see the difference. I would not use RAID0 which offers no redundancy if one drive fails losing both, another important reason to always run backed up.
My System SpecsSystem Spec
19 Jul 2012   #7

Win 7 Ultimate 64

hi gregrocker, to put is simply - you were right

the problems with the booting were:
a) active partition on the raid field (fixed)
b) the F8 Advanced recovery options are not working (to be fixed)

The system is now entirely booting from the SSD, however, the recovery option is not working. I tried to rebuild it, but it did not fix the problem. Any ideas for a simple solution?

Performance - after the switch to AHCI, the booting time decrease by 20s (!). It changed from 60s to 40s (according to event viewer) - the HDD light was flashing nearly all the time (unlike in the RAID mode, where it stops frequently to take a breath). (I personally would blame the AMD driver implementation...and I get the feeling that AMD are getting worse and worse with driver support ( the graphic cards, mainboard, controllers), but this is a different story)

However, it was not possible to import the raid field into the system, therefore, I am stuck with the raid mode until I get more space to migrate the disks. Windows can strip data between multiple disks (raid 0). I have still to find out whether such a raid field can be accessed from other OS (eg. linux)

A strange thing was that when I removed the raid field and booted into Windows (nothing changed in bios, still in raid mode), Windows loaded a new driver for the SSD and required a reboot. This is strange as I have rebooted the PC 100 times since the SSD install and the RAID field is said to have no influence on a single SSD disk. Obviously it has!

many thanks for your time and input
My System SpecsSystem Spec
19 Jul 2012   #8

Win 7 Ultimate 64

A little bit of RTFW and Visual BCD Editor and it's now working and booting.

Thanks gregrocker for your help
My System SpecsSystem Spec
19 Jul 2012   #9
Microsoft MVP


Did you run Startup Repair - Run 3 Separate Times with only the SSD plugged in and marked Active?

This should have repaired the link to F8 System Recovery Options.
My System SpecsSystem Spec
19 Jul 2012   #10

Win 7 Ultimate 64

Yes I did run it three times - the first time it took minutes to complete but the second and third time I got a message that nothing was found (with restarts in between). I discovered that the recovery PE file was tempered by Windows 8 preview, that I once tried. Nothing is ever straightforward, is it? :-D
My System SpecsSystem Spec

 Migrating from RAID to AHCI, Win 7

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