We help IT Professionals succeed at work.
Get Started

Storage - Expanding a Dell RAID 5 array above 2TB when MBR in place – Possible?

Last Modified: 2016-11-23

I had a Dell PowerEdge server running Windows Server 2008 R2 and I wanted to expand the storage of the RAID 5 array.
To give some background it’s a PowerEdge T610 with 8 physical hard drive bays.

Before the change the server had these physical drives:

2 * 300GB  - Forming a RAID 1 mirrored configuration where the C partition and OS lives
4 * 600GB – Forming a RAID 5 configuration giving about 1.6TB of storage. This forms the D drive on the server.

Speaking with Dell we decided to purchase another 2 * 600GB to make use of the two empty bays with the intention of adding 1.2TB of capacity to the existing RAID 5 array and expanding the D drive. This would make about 2.6TB available in the RAID 5 array.

Dell informed us this would be pretty much plug and play.

In some ways it is, we have added the drives and the server can see them via the OPENMANAGE configuration software and I can amend the array to add the two new disks, but when adding the drives to the array the software pops up a dialogue which says:

“Please verify that your operating system, including any updates or modifications, supports a virtual disk of this size, do you want to proceed?”

This led me to ask Dell support, but I have received contradictory information from different engineers and I’m not sure if there is risk in proceeding.

It seems that as the drives are MBR, we can only address 2TB of space so I have to convert to GPT.

The server is an a live environment with the data backed up to a cloud storage solution. I don't have a local quickly accessible backup at present.

Through my investigations I am left with the following questions.

1)      Generally I’m open to what the best approach to achieving this so open to any general suggestions.
2)      To convert to GPT, it seems I would lose the data on the D drive? IF anyone knows a way of not doing this, let me know, but if not, what is a method where I can easily backup and restore and ensure everything is retained as it was. Therefore for example
3)      Someone said, if I am not bothered about expanding D and wanted to create a new partition E, I could look to expand D to 2TB and have the remaining unallocated space to create an 800GB E drive. Is this true?
4)      If I were to proceed despite the warning, is there any risk to the data?
5)      I am right in thinking that in Windows Server 2008 R2, I can dynamically expand and shrink the size of drives without needing third party tools like partition magic?
6) Am I right in thinking that all of this work does not pose any risk to the C drive (which is in a mirrored RAID 1 array and contains the OS and boot partition)

Any general information on this would be great.
Watch Question
Most Valuable Expert 2015
This problem has been solved!
Unlock 4 Answers and 12 Comments.
See Answers
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE