Cannot Convert Disk to GPT and limited to 2 TB

Hi everyone,

We've got a strange issue and hope someone has some ideas or
suggestions. We have a cluster consisting of two Windows 2003
Enterprise R2 SP2 servers, one active, one passive. It already had
two SAN LUN, a 2 TB and 1.5 TB.

Since we have more storage on our SAN and GPT disks can be bigger than
2 TB, we presented two more SAN LUNs to it, an 11 TB and 4.7 TB. We
were going to convert them into GPT disks to use the full size of the
luns. But when I right-click on the disks, Convert to GPT Disk is
greyed out.

I initialized the 11 TB disk and that resulted in it splitting it into
two parts, a 2 TB and 9 TB part. They are not partitions because when
I right click on the 2 TB part, it gives me an option to create a
partition.

We have already implemented GPT disks of larger than 2 TB on another
Windows 2003 R2 SP2 server but it's not clustered. So we know it
works.

I'd appreciate any help. Thanks in advance.

Greg

On Jan 15, 9:03 am, Greg H <gphal...@gmail.com> wrote:
> Hi everyone,
>
> We've got a strange issue and hope someone has some ideas or
> suggestions. We have a cluster consisting of two Windows 2003
> Enterprise R2 SP2 servers, one active, one passive. It already had
> two SAN LUN, a 2 TB and 1.5 TB.
>
> Since we have more storage on our SAN and GPT disks can be bigger than
> 2 TB, we presented two more SAN LUNs to it, an 11 TB and 4.7 TB. We
> were going to convert them into GPT disks to use the full size of the
> luns. But when I right-click on the disks, Convert to GPT Disk is
> greyed out.
>
> I initialized the 11 TB disk and that resulted in it splitting it into
> two parts, a 2 TB and 9 TB part. They are not partitions because when
> I right click on the 2 TB part, it gives me an option to create a
> partition.
>
> We have already implemented GPT disks of larger than 2 TB on another
> Windows 2003 R2 SP2 server but it's not clustered. So we know it
> works.
>
> I'd appreciate any help. Thanks in advance.
>
> Greg

Just in case anyone else runs into this problem, we had to install the
following hotfix:
http://support.microsoft.com/kb/919117/en-us
And here is a link someone sent regarding using diskpart
http://support.microsoft.com/kb/300415
with the hotfix and dispart, our cluster servers were able to convert
them to gpt.