Intel RAID 1 will not Boot unless Non RAID Drive is attached

enigmasolutions used Ask the Experts™

My Win 2008 R2 Server will not boot unless I have a 5th sata drive.

Here is how I got into this trouble...

I have ASUS P88 WS motherboad
I have a pair of RAID 1 drives for the C-Drive (Win O/S)
And a pair of RIAD 1 drives for the E-Drive (Data)

One of the C-Drives failed.  So I added a new drive to rebuild the raid - which worked.
I then mistakenly thought the broken drive may be ok - So I plugged it into SATA port 1 (which in theory is a Non-Raid sata port).  I thought I may be able to low level format it (but didn't get far).

NOTE: the "broken" drive is definitely NOT part of the Intel Raid - its serial# shows as a Non-RAID in the Crtl-I screen.  And the other 4 drives all correctly show as part of the two RAID volumes.  Also this is confirmed in the Intel Matrix Storage Manager Screen.

Now if I remove the "broken" drive then Windows won't boot.

I guess I can live with the "broken" drive chewing up power.  But it bothers me.

How can I remove this drive.
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It sounds like its not at fully hardware raid since it need one master disk to boot from.

Does it change anything if you change the 2 disks on the raid c: - so one original disk is on the other cable . ?

Any way it sounds more like the broken disk holds the MBR - in this case I would repair the windows OS -
Use this guide to repair your system - full backup first or make a backup image of C:
Top Expert 2013

what drive is the bios pointing to for booting?
Most Valuable Expert 2015

Are you sure you have told us the correct model number for the mainboard? I can't find any "ASUS P88 WS" board on the Asus site...

Anyway, it looks like you are using the cheap fake-raid onbaord controller and not a proper RAID controller. NEVER use the RAID functions of such fake-RAID controllers, they are absolutely unreliable crap. Disable on board RAID and instead set the controller to SATA or AHCI mode, and then rather use the built-in Software RAID of your OS. That is much more reliable and also faster, as the OS can read data from both drives simultaneously, only expensive hardware RAID controllers have such functionality, and they don't do it optimally like the OS RAID function does.
That... Is a bunch on nonsense... Hardware RAID 1 on ASUS works well and I take it's reliability ANY day over crapy Microsoft Software RAID.
A single power hick up and by-by RAID when in software.

It looks like the bad HD ID is  recognized  in the configuration.

First make sure that you have a good backup because things can go wrong really fast!

Here what I would do...

Break the mirror
Take one of the what was a mirror drives  out  ands well as the "bad" drive
If you can boot... Rebuild the mirror

Alternately you can try the same w/o breaking the mirror but pulling out the drives as mentioned above.
Most Valuable Expert 2015

You are incorrect. That isn't hardware RAID, but only fake-RAID. Windows built-in RAID is far better. Besides, a power hickup will have the same results on fake-RAID controllers. Only real hardware RAID controllers with a battery backup have some protection against that.
Yes, there is the "academic" solution or... there is the real world practical hands on expertise.

I have worked with Asus "fake" controllers for a long time. And if budget permits... I recommend dedicated RAID controller over anything else.
This said Asus MB's with their RAID are fantastic and are by far more reliable compared to software RAID.
Many times the ASUS RAID is the last man standing over any solution.
Most Valuable Expert 2015

No OS Software RAID is much better. It may have been a bit different with old OS's like XP or 2003, but with Vista/2008 OS RAID is absolutely fine, and with 'nix type OS's anyway, and as I mentioned earlier, you also get better performance. Besides, you can easily move the array to other hardware and it is still the data is still accessible, without needing the same "fake-RAID" controller or recovery tools. Although of course such measures shouldn't be necessary if the backups were done properly.


Thank you all for the fantastic answers.  And the debate on HW v SW RAID is really interesting.

I have to make changes to this server after hours.  So stay tuned.

Just to throw a spanner in the works on the debate... one of my clients has a Gigabyte MB with two pairs of RAID 1 (one for the OS and one for data) - this was my idea.  Only problem is (my hardware installer didn't tell me) that this MB has ONE pair of Intel RAID for the OS and ONE pair of Motherboard Gigabyte RAID for the data.  And the Gigabyte RAID would only work if the O/S booted.  Consequently when the RAIDS both broke, after huge trouble, I ended up getting rid of the second RAID all together and just put the data on the C-Drive.  I have since been told that the Gigabyte Raid is software raid (but I wouldn't know).

Interestingly this system had a similar problem, where it wouldn't boot unless this extra "Non-RAID" drive (with nothing on it) was connected to a non RIAD sata port - go figure ???
Most Valuable Expert 2015

Both the intel and the other RAID on that board were fake RAID. There are many boards that have 2 fake-RAID controllers. But whether it is intel or nvidia or whatever doesn't really matter, they are all crap. The only RAID controllers that are usable are real hardware RAID controllers like those made by adaptec etc., but those are expensive and you won't find them built into mainboard's, except maybe server boards or high end workstation boards.
I agree with Rindi -  I think the failed disk holds the boot section and MBR - so you can rebuild it using the guides I sent - Dont worry you will succeed - have nice day all ( here its 7.16 Am ) just waking up


Hmmmmm so Rindi, you really think I should destroy the on board RAID and make use of my drives for OS Software RAID.  And you believe that OS SW RAID is better than a single HDD.

If so can you provide links/info on
a) how to kill the Motherboard RIAD / ie convert to Non RAID bootable O/S
b) How to setup O/S RAID
c) How to wipe the extra RAID Drives for re-use as S/W RAID Drives

Many years ago (10+) I had adaptec RAID and hated it to be honest.  What worried me the most was not the broken raids but what I would do if the adaptec controller failed and how I would go about finding a replacement in a hurry.  

BTW MB is ASUS-PB8-WS (I think - hard to read text on MB).

In this case this server is not worth forking out $ for an adaptec controller.

Insidertech, I appreciate your arguments.  I can't help thinking you may be right too.  I have been conditioned to believe that HW RAID is better.  After all I have never lost data on the Intel MB RAID.  Sure it has caused me a LOT of grief and outright fear when RAIDs fail.  My gut feel is that H/W RAID means the H/W writes to both disks at the hardware level so it is better.  But according to Rindi, this is a false assumption.  Arrrrggghhhhh.

Gee I wonder which of you two are correct?  Insidertech says he has lots of experience backing his finding.  Rindi, I presume you have similar first hand experience to support your findings.

The will be a day of reckoning soon on this debate !!!

In the mean-time I will have a crack at repairing the MBR.  

Thanks for the tips ServerService!


Hmmm I searched this term in Google...

Intel Motherboard RAID vs Windows RAID 1

And there was an even split in favor of one versus the other.
But not a lot of hard evidence.
Most Valuable Expert 2015

Go into the BIOS and change the controller's setting from RAID to AHCI (or SATA or enhanced, whatever it is called in the BIOS). Then make sure you select the correct HD to boot from in the boot order.

If your system can't find the boot device after that, boot up with Paragon's free Rescue Kit and allow it to repair your installation. When done try booting again.

Once the OS is up and running, go into diskmanagement and convert the disks to dynamic. You may need about 8MB unpartitioned space for that to be available, so you may have to shrink a partition a little before that. Once you have dynamic disks you can just create a mirror within diskmanagement.


Thanks Rindi.

But before I do that I want to get my system booting (without that extra drive in there).

I notice that in Server Manager / Disk Management that I can see my drives...

Refer to picture below...

It looks like the "System" is on the drive I want to remove.
But I suspect my C: drive may be bootable - if only I could convince the PC that the System is there.

QUESTION - Will this RK-Express program fix the problem?

Photo of my server drives
Most Valuable Expert 2015

Use the paragon utility I mentioned above, it should be able to fix any boot problems.


woops sorry - didn't realise


thank you


Interesting, the Paragon utility did not fix the problem.
It could not find a Windows O/S Boot Sector to Repair.
(unless I had the 5th drive in - of course).

It is like my booting drive is spread across two drive systems - the 5th Drive (Drive 0) with the MRB and the rest of the O/S loading from the C-Drive (Drive 1 - RAID).

If only I could copy the MBR from the 5th Drive back to the boot partition of my C-Drive.

So I am back to booting with the extra 5th drive on the non RAID port.
BTW, in my attempts to clean this 5th drive I managed to erase the data partition.
So I am not thrilled about trying to re-join it to my RAID (by removing one of my current C-Drives).

I suppose I could re-install windows on a totally new set of drives (and them somehow migrate the current setup to the new install).  But that frightens me too.  I have other Hyper V virtual servers on my E-Drive (Data Drive).  I wouldn't even know where to start on this idea.
Most Valuable Expert 2015
Try using a cloning utility to clone the "system Reserved" partition of the drive you need inside the system so it boots up to the disk you want to boot from. A good, OpenSource, free utility for that is CloneZilla:


Thanks I will have a goo at it tomorrow night.  Got to stop now.

ColeZilla looks a bit tricky to install onto a DVD (for a lazy non linux user)
But I will give it a go tomorrow.

Actually I found an ISO for CloneZilla on Source Forge.

Here are a few more tools.

Stay tuned...
Most Valuable Expert 2015

It fits fine on a CD (I wouldn't waste a complete DVD for that). You can also get it on a USB stick using Unetbootin. Actually with that tool you don't even have to manually download it, you can just select CloneZilla from the drop down list, and then it downloads the iso and extracts it to a USB stick. But you can also manually select the iso you downloaded and use that:


Sorry, I haven't had time to try Clonezilla yet, but will do over the weekend.
If you want to try and clone the failed disk - then I would recommend Acronis Trueimage - make a boot cd and clone the disk - It takes 5 min.
Here is an idea if you are brave...

This is predicated on the assumption that the MBR is on the orphaned "bad" drive.

1. Delete the 100 MB volume on the drive 0 which is actually A RAID pair
2. Create software mirror using the orphaned disk 1 100 MB partition.
3. After all is in sync break the software mirror.

This should work as the OS does think that the drive 0 is a single drive and not mirrored one.

Alternatively pull one of the mirror drives out so you have a back up if something goes wrong.

One more thought... Since the orphan drive failed in your original RAID it is a matter of time when it will fail completely an you may be screwed so I would not recommend having this arrangement for very long.
I would not suggest to delete the system partition cos then the server will not boot.

If you have cloned the disk - then you should rebuild the mirror


I am not having much luck.  But working on it now...


Woo hoo... I got my server back.  Yeah...

But I couldn't get the MBR restored.  And copying partitions around was a nightmare.  It was always going to be a long shot.

Lucky for me I put the operating system on the C-Drive and I have my really important data on the D-Drive.  Actually I had two Virtual machines running off the D-Drive.  So losing my C-Drive wasn't so bad.

Actually re-installing Win 2008 Server R2 was quite easy, and re-attaching the virtual servers was easy too.

But thank you for all the fantastic support.  It was interesting!


Thank you to ALL contributors.


FYI, This tool looks really good.  I wish I had found it earlier...

Has anyone had experience with it?
Top Expert 2013

me not, i use the paragon software :


FYI - I tried this 
but it was no good for Servers.  

I think the server version is about $1000.
Perhaps OK as a regular backup.
But no idea for a home server, once off disaster recovery.

Partition Wizard looks interesting.  May have helped with what I needed.  One day I may try it out.
I used it but I also like tools from easeus.

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