"Add mirror..." grayed out on 2 identical drives

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Chaz Howell

Jul 12, 2005, 7:29:01 PM7/12/05
Basically, we're running a Dell server with a Xeon processor and SBS installed.

We had two 80GB drives that were running as dynamic drives, software
mirrored through the Microsoft Disk Manager, and were working just fine.

Disk0 (C: drive with MBR) crashed. A dell service guy came out and moved
Disk1(D:) to become Disk0(C:) and installed an identical hard drive to become

Here is a quote from one of our guys who dealt with this issue before I came

As far I can understand (the tech that Dell send was a little retarded) the
Disk 0 (MBR) failed and when he put in the new disk the system would not boot
because it was looking to MBR on the new disk. Without any additional
knowledge I did break the mirror and swapped the drives so the system could

Now, the system boots and runs just fine. Both disks are recognized in the
Disk Management tool. But, and here's the catch, no matter what I do, I
cannot get a software mirror to run again.

Specifically, when I create a new volume on Disk1(D:), the new drive, the
"mirrored" option is grayed out. Also, if I right click on the volume on
Disk0(C:) or Disk1(D:) the "add mirror..." option is grayed out.

Basically, I'm stuck. I just cant' get the replacement drive to create a
mirrored volume to get mirroring (RAID1) running again.

Once caveat: Althought the disks are identical (DM reports them in their
repsective properties windows as being Maxtor 6Y080M0 disks) they don't seem
to be the exact same size. Disk0(C:) says its capacity is 74.5 GB and
Disk1(D:) says its capacity is 74.38GB while it's unallocated (no volumes).

Anything you could do to help, or anyone you know who you could forward this
email to would be greatly appreciated. I came on as a tech guru to help this
company out, and now I kind of look like a poser. Since, I can't fix this
silly disk issue. Help a brother save face and earn good karma!


Jul 12, 2005, 8:02:01 PM7/12/05
Are you sure both disks are converted to "Dynamic"?

Merv Porter [SBS-MVP]

Jul 12, 2005, 9:26:23 PM7/12/05
Disk1 must be at least as large as Disk0 if you have only one partition on
Disk0. So you need to change the partition size on Disk0 to accomplish your

You could use Ghost 2003, or similar software, to image Disk0 to a spare
drive (maybe an External USB drive), then restore it to Disk0 while
adjusting the partition size of Disk0 so that you have, say, a 72 GB
partition with your data and a 3 GB (approx.) partition with no data on it.
(Of course, make sure you have a good backup of Disk0 before doing this).
In a pinch, you could also use Disk1 as a temporary location to hold the
image of Disk0. You would then later delete any partitions on it so it
contains only unallocated space before the mirroring procedure.

Note that Ghost will restore the image to Disk0 as a "basic disk" and not a
"dynamic disk". After image restoration, you should be able to convert
Disk0 to dynamic and mirror it's 72 GB partition to Disk1. The other 3 GB
partition can just sit there, unmirrored.

Before you do the mirror to Disk1, create a small partition on it, format it
NTFS and then delete it so that Disk1 is all unallocated space. Then do the
mirror. This will update the MBR on Disk1 so that it will be bootable if
Disk0 fails.

(Partitions on Basic disks are called Volumes on dynamic disks).

Merv Porter [SBS MVP]
"Chaz Howell" <ChazH...@discussions.microsoft.com> wrote in message

Jenny wu

Jul 13, 2005, 8:56:38 AM7/13/05
Hi ChazHowell,

Thanks for posting here.

many thanks for Merv and D's input.

For your description, I understand that you can not get mirror after you
changed disk. If I am off base, please don't hesitate to let me know.

In order to provide you with efficient support, and to relieve you of the
burden of trying unnecessary troubleshooting steps, please assist me in
confirming the following points:

The following requirements are necessary if you want to create mirror for
system and boot files in Windows 2003:

1. At least two hard disk drives; IDE, SCSI, or mixed architecture is

2. The second drive needs to be at least the size of the volume on which
the operating system boot and system files reside to permit mirroring. Do
you have the enough free space?

3. The Windows 2000 system and boot files need to be together on the same
volume to be mirrored. Does your Windows 2000 have system and boot files
together on the same volume?

4. The disk must be dynamic disk. Which third party tool did you use to
make the disk as dynamic disk?

The following solution describes how to mirror the system and boot
partition in Windows Server 2003, please try to test.

This scenario is based on the assumption that the system and boot files
are located on disk 0 and that disk 1 is unallocated space.


- At least two hard-disk drives; IDE, small computer system interface
(SCSI), or mixed architecture is permissible.

- The second drive must be at least the size of the volume on which the
operating system boot and system files reside to permit mirroring.

- The Windows Server 2003 system and boot files must reside on the same
volume to be mirrored.

Upgrade to Dynamic Disks
To upgrade a basic disk to a dynamic disk, follow these steps:

1. Before you upgrade disks, quit any programs that are running on
those disks.

2. Right-click the gray disk description panel, and then click "Upgrade
to Dynamic Disk".

3. If the second disk in not a dynamic disk, follow these steps to
upgrade it to a dynamic disk.

Mirror the Boot and System Volume
NOTE: Partitions are referred to as <volumes> when the disks are dynamic.

1. Disk 1 must be unallocated space before you can proceed with

2. Right-click disk 0 (which contains the boot and system files), and
then click Add Mirror.

3. A dialog box opens in which any disk on your system that is
available for mirroring is displayed. Select the disk of your choice
(in this example, it is disk 1), and then click Add Mirror. Both disk 0
and disk 1 will now have the same color code, the same drive letter,
and the volumes will have the status note "Regenerating" displayed
while the information is being copied from the first disk to the second
disk. The system will automatically size the volume of the new mirror
to the same size as that of the original boot and system volume.

4. If you now want to boot from the new mirrored disk, you have to
change the Boot.ini ARC path that points the computer to the partition
in which the system files are located.


For additional information, click the article
numbers below to view the articles in the Microsoft Knowledge Base:

KBLink:113977.KB.EN-US: Booting From Mirror After Primary Partition Is

KBLink:120227.KB.EN-US: Steps to Recover a Failed Mirrored System/Boot

KBLink:114779.KB.EN-US: Overview of Disk Mirroring (RAID Level 1) in
Windows NT

I am currently standing by for an update from you and would like to know
how things are going on your end. I am always happy to be of further

Have a nice day!

Best Regards,
Jenny Wu
Microsoft Windows Online Support

Chaz Howell

Jul 14, 2005, 11:51:07 AM7/14/05
Dear D,

Thanks for you reply. Yes, both disks have definitely been converted to

Chaz Howell

Jul 14, 2005, 11:56:06 AM7/14/05
Dear Merv,

First of all, thank you very much for your post.

I think you have hit the nail on the head in the sense that the drives are
not being reported as being the same size, even though they are "identical"
drives of the same make from the same manufacturer. By the way, I tried to
talk to Maxtor about this, and their response was that if the system
recognized the drive, then they no longer have an obligation to support it.
Thanks, guys. I'll be sure to run down to Fry's and buy some more of your

Anwyay, all flaming aside, I will most definitely try your solution and
post back to this thread with the results.

Once again, thank you for your help.

-Chaz Howell

Chaz Howell

Jul 14, 2005, 12:02:01 PM7/14/05
Dear Jenny,

Thanks for taking the time to reply to my post.

I took a look at your post. I think Merv's post above yours has given me a
solution path to try. But, I did want to answer your questions.

1. Yes, there are two IDE hard drives that are identical make and manufacturer
2. The second drive (which contains no visible data) is slightly smaller
than its twin?!? I think this is why the "add mirror..." command is grayed
out when I right-click on drive0. Of course, this would prevent me from
following the steps you have given with regard to mirroring the drive.
3. the system and boot files all reside on disk0
4. Both disks are Dynamic disks. I used the Windows SBS 2003 Disk Manager to
make them both Dynamic. I did not use any 3rd party software for this.

I think the issue is that for some reason disk1 says it's ever so slightly
smaller than its twin, disk0.

I'm going to try Merv's solution path in his post to this thread to reduce
the volume size on disk0 to match the volume size of disk1 and then see if
the "add mirror..." menu item is available again.

Thanks for you help.

-Chaz Howell

Jenny wu

Jul 15, 2005, 7:14:00 AM7/15/05
Hi ChazHowell,

Thanks for your update.

I appreciate you time and effort. I am currently standing by for you about
the test result. I am always happy to be of further assistance.

Have a nice weekend!

Chaz Howell

Jul 15, 2005, 11:21:06 AM7/15/05
Dear Jenny,

Thanks, I appreciate it.

A quick update...

I downloaded a diagnostic tool from Maxtor that checks the integrity of
their hard drives and does low-level formatting. I ran that tool on the C and
D drives and found them to be OK.

Next, I low-level formatted the D drive in the hopes that it would return it
to the same size as its identical twin, the C drive. It did.

Then, I tried to create a volume of type "Mirror" on the D drive. It would
finally allow me to choose the mirror option in the create volume window
(whereas that option was grayed out before).

Interestingly, while it would let me create a mirror volume, it would only
let me create one 7MB in size.

I'm guessing that since the mirror was broken on the original two drives
when a replacement drive was added to the system after the crash of the
original C drive (D became C and the replacement drive became the current D
drive) that there is some remanant mirror information on the current C drive
that is preventing me from creating a mirror volume on D that is the same
size as the volume currently taking up the entirety of the C drive.

In simple terms, since I low-level formatted the D drive the "add mirror..."
menu option is available again when I right click on the volume on the C
drive. Also, the option to create a mirror volume on D is no longer grayed
out since the low-level formatting of the D drive. But, I can only create a
mirror volume on D that is 7MB in size.

Is there some way to fix this so I can create a mirror volume on D that is
the same size as the volume on C (there is only one volume on C which is
about 74.5MB) or will I have to back up C, reformat it, make it dynamic MBR,
create a new volume and then restore the backup to C before trying to create
a mirror volume on D in an effort to add a mirror to the C drive?

Confused yet?

Thanks, in advance.


Merv Porter [SBS-MVP]

Jul 15, 2005, 12:17:36 PM7/15/05
Is all of the D: drive listed as "unallocated" space before you try to
create the mirror?

Merv Porter [SBS MVP]
"Chaz Howell" <ChazH...@discussions.microsoft.com> wrote in message


Chaz Howell

Jul 15, 2005, 1:15:05 PM7/15/05
Dear Merv,

Most definitely, yes.

I did a low-level format of the D Drive that wrote zeros to every sector on
the hard drive. Completely wiped it. Then I went into the Disk Manager and
re-actived that disk. Once the disk was recognized, I made it a Dymanic disk
of type MBR. I right-clicked on the unallocated space and chose "New Volume"
and got a new window prompting me to choose which kind of volume I wanted. I
chose mirror.

I then takes me to a series of screen that is asking me to choose which two
disks to mirror. I chose C, as D is already listed as one of the disks. At
that point the it only allows me to create a 7MB mirror volume.

It's like it's looking at the C drive, seeing that it has a volume that
already has a mirror associated with it (the broken mirror from when the
original drive failed) and then it says "Well, you can't use that volume on
C. I'll just give you an arbitrary 7MB that happens be left at the end of the
C drive to mirror onto the D drive."

You see, we had a C and a D drive. The C drive only had one volume on it
that took up the whole disk. It was being mirrored onto the D drive. The C
drive crashed and a Dell tech came out and moved the D drive into the primary
master disk position (C dirve) and then intalled a new drive as the D drive.
He then "broke the mirror" and packed up his gear and split. (Dell does not
support software raid.)

So, that is what I'm left with. A C drive that was the old D drive, and a
new D drive that won't allow me to create a mirror volume of more than 7MB.

Does that make sense?


Merv Porter [SBS-MVP]

Jul 15, 2005, 7:17:11 PM7/15/05
Humor me here...

Take the D: Drive back to an "unallocated space" state and use the following
instructions to create the mirror...

Mirroring Drives in Windows 2003

Merv Porter [SBS MVP]
"Chaz Howell" <ChazH...@discussions.microsoft.com> wrote in message


Chaz Howell

Jul 18, 2005, 2:19:05 PM7/18/05
Dear Merv,

I followed the instructions to the letter (a few times).

The drives started to sync but, the process just stopped after 1% - 2%

One thing: I ran the diagnostic software that the hard drive manufacturer
puts out and it said that Disk0 is failing.

So, I got a brand new drive sent to me from Dell. That's my day, today...
I'm going to try and clone the C drive to the D drive, move the D drive into
Disk0 position, hope that it boots correctly, install the brand new drive
into D position, and see if I can mirror it then.

Wish me luck!!!

Thanks for all you efforts to help me.

Merv Porter [SBS-MVP]

Jul 18, 2005, 2:30:48 PM7/18/05
Thanks for the update. Keep us posted Chaz!

Merv Porter [SBS MVP]
"Chaz Howell" <ChazH...@discussions.microsoft.com> wrote in message



Apr 17, 2019, 11:37:31 PM4/17/19
It's important that the disk you are trying to add (which should be same size or bigger than the source disk) has no volume. So you need to 'delete volume. Once Disk Management finds a sufficiently big unassigned disk, the 'Mirror' option on the source disk will no longer be greyed out.
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