Tech Library
| Product Category | VDC Compute Disk, Compute Configuration |
|---|---|
| Product Family | VDC Premium Disk |
| Trouble Type | MAC |
| Support Tier | ITaaS |
| Last Updated | 30 July 2019 |
Disks that are configured with the Master Boot Record partition scheme can only support up to 2tb of allocated space, whereas GUID Partition Table scheme does not have that limitation. Disks that contain Windows OS boot data must be configured with the MBR scheme. MBR to GPT partition scheme conversions must only be done on data volumes. Make sure you get a snapshot of the server before proceeding, work with the cloud team to make sure the data store delta can handle a snapshot overnight. (Reference link: https://miloszengel.com/how-to-convert-partition-from-mbr-to-gpt-scheme-on-windows/)
Download gptgen
GPT Gen is a free and open-source command line tool that converts disks with the MBR scheme to GPT scheme.
https://sourceforge.net/projects/gptgen/
Extract Files
- GPT Gen is downloaded as a .zip file, leave the .zip folder in the Downloads folder.
- Extract all of the files to the Downloads folder.
Verify Disk Number
- Launch an elevated command prompt.
- Run diskpart | list disk
- Note the number of the disk you are going to convert.
- End the diskpart command: ctrl + C
Run GPT Gen
- Change directories to the folder that contains the gptgen.exe application.
- The application is nested inside one more folder after extraction.
- After you navigate to the directory, run gptgen.exe -w \\.\\physicaldriveX where X is the number of the disk to be converted (The screen shot has disk 4 highlighted.)
- If prompted to verify block/sector size (it is typically 512b) run: fsutil fsinfo ntfsinfo diskletter:
- Look for the value in "Bytes per Sector."
- Put in the block size and hit Enter.
- After the conversion process completes, reboot the server.
Verify Partition Scheme Change
- Open the Disk Management console.
- Open the disk properties (not the volume)
- In the volumes tab - the partition scheme information is mid-way through the window, should read as GPT (GUID Partition Table).
- Keep snapshots for 24 hours ideally, work with CE to delete snapshots after the maintenance window.
