4TB WD Only Recognized 2TB by RAID Controller, How to Fix

I have a backup server with a RAID controller. I have 6 4TB Seagate drives, and I want to replace the old drives with WD drives of the same size. But the Adaptec RAID controller only recognizes 2 TB. What should I do? Thanks.

It is a common error that a 4TB drive is only recognized as 2TB of space on the computer. Don't worry about this being a controller issue, as you already have a 4TB drive on the controller. If this is a new WD drive, you will need to initialize it first. During the initialization process, you need to select the correct partition style.

The MBR and GPT partition styles determine the maximum drive you can recognize on your computer: MBR supports only 2TB drives, while GPT has no limit.

To recover the full capacity of 4TB, you need to convert MBR to GPT. EaseUS Partition Master Server can ensure you can do the partition conversion while breaking the limit and avoiding data loss.

Don't worry about the difficulty of the operation. The tool has a simple interface. Even if you are new to computers, you can figure out how to solve the problem of "4TB WD only recognized 2TB by RAID controller":

Step 1. Launch EaseUS Partition Master and go to "Disk Converter."

Step 2. Select Convert MBR to GPT and click "Next."

Step 3. Select the target MBR disk and click "Convert."

In Windows Server, you can also use commands to complete the conversion. However, the process is more complicated, so please choose an appropriate option.

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