How to Fix Windows Server 2019 Not Recognizing 4TB RAID 1 Drives

Learn how to solve the problem of Windows Server 2019 not recognizing 4TB RAID 1 drives on a Dell PowerEdge R720XD server with a PERC H710p controller.

If you have a Dell PowerEdge R720XD server with a PERC H710p controller and you want to install 4TB drives in RAID 1 configuration, you may encounter a problem where Windows Server 2019 only recognizes the drives as 2TB. This article will explain why this happens and how to fix it.

Why Windows Server 2019 Only Sees 2TB Drives

The most likely reason why Windows Server 2019 only sees 2TB drives is that the disk partition style is set to MBR (Master Boot Record) instead of GPT (GUID Partition Table). MBR is an older partition scheme that has a limit of 2TB per disk, while GPT is a newer partition scheme that supports disks larger than 2TB. MBR also has a limit of four primary partitions per disk, while GPT can have up to 128 primary partitions per disk.

To check the disk partition style, you can use the Disk Management tool in Windows Server 2019. To open Disk Management, you can press Windows + R, type diskmgmt.msc, and press Enter. In Disk Management, you can right-click on the disk and select Properties. In the Properties window, go to the Volumes tab and look at the Partition style field. If it says Master Boot Record (MBR), then you need to convert the disk to GPT.

How to Convert MBR to GPT in Windows Server 2019

There are two ways to convert MBR to GPT in Windows Server 2019: using Disk Management or using Diskpart. However, both methods require deleting all the partitions and volumes on the disk, which means you will lose all the data on the disk. Therefore, before you convert the disk, you should back up any important data on the disk to another location.

Method 1: Using Disk Management

To convert MBR to GPT using Disk Management, follow these steps:

1. Open Disk Management and right-click on the disk you want to convert. Select Delete Volume for each volume on the disk until the disk becomes unallocated space.
2. Right-click on the disk again and select Convert to GPT Disk. The disk will be converted to GPT and you can create new partitions and volumes on it.
3. To create a new partition, right-click on the unallocated space and select New Simple Volume. Follow the wizard to assign a drive letter, a file system (NTFS or ReFS), and a volume label. You can also adjust the size of the partition as needed.
4. Repeat the previous step to create more partitions if you want. You can also extend or shrink the partitions later by right-clicking on them and selecting Extend Volume or Shrink Volume.

Method 2: Using Diskpart

To convert MBR to GPT using Diskpart, follow these steps:

1. Open an elevated command prompt by pressing Windows + X and selecting Command Prompt (Admin).
2. Type diskpart and press Enter to launch the disk partitioning tool.
3. Type list disk and press Enter to see the list of disks on your system. Note the disk number of the disk you want to convert.
4. Type select disk x and press Enter, where x is the disk number of the disk you want to convert.
5. Type clean and press Enter to delete all the partitions and volumes on the disk.
6. Type convert gpt and press Enter to convert the disk to GPT.
7. Type exit and press Enter to exit Diskpart.
8. To create new partitions, you can use Disk Management or the format command in the command prompt.

Frequently Asked Questions (FAQs)

Question: Can I convert MBR to GPT without losing data?

Answer: No, you cannot convert MBR to GPT without losing data using the built-in tools in Windows Server 2019. You need to delete all the partitions and volumes on the disk before you can convert the disk partition style. However, there are some third-party tools that claim to be able to convert MBR to GPT without data loss. However, you should always back up your data before using any disk conversion tool, as there is always a risk of data loss or corruption.

Question: Can I convert GPT to MBR in Windows Server 2019?

Answer: Yes, you can convert GPT to MBR in Windows Server 2019 using the same methods as converting MBR to GPT. However, you should be aware of the limitations of MBR, such as the 2TB disk size limit and the four primary partitions limit. You should also back up your data before converting the disk partition style.

Question: Do I need to convert MBR to GPT to install Windows Server 2019?

Answer: It depends on whether you want to boot from the disk or not. If you want to boot from the disk, you need to convert MBR to GPT if the disk is larger than 2TB or if your system supports UEFI (Unified Extensible Firmware Interface) boot mode. UEFI is a newer firmware interface that replaces BIOS (Basic Input/Output System) and requires GPT disks to boot from. To check if your system supports UEFI, you can open System Information by pressing Windows + R, typing msinfo32, and pressing Enter. In System Information, look at the BIOS Mode field. If it says UEFI, then your system supports UEFI boot mode. If it says Legacy, then your system supports BIOS boot mode.

If you do not want to boot from the disk, you can use either MBR or GPT for the disk partition style. However, GPT has some advantages over MBR, such as supporting larger disk sizes and more partitions.

Summary

In this article, we have explained how to fix the problem of Windows Server 2019 not recognizing 4TB RAID 1 drives on a Dell PowerEdge R720XD server with a PERC H710p controller. The problem is caused by the disk partition style being MBR instead of GPT. We have shown how to convert MBR to GPT using Disk Management or Diskpart, and answered some frequently asked questions about disk conversion. We hope this article has been helpful for you.

Disclaimer: This article is for informational purposes only and does not constitute professional advice. You should always consult a qualified IT technician before making any changes to your system. We are not responsible for any data loss or damage that may result from following the instructions in this article.