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Oracle Linux: How to Convert a Disk Partition Table from MBR to GPT (Doc ID 2903259.1)

Last updated on OCTOBER 20, 2022

Applies to:

Linux OS - Version Oracle Linux 7.0 and later
Linux x86-64
Linux ARM 64-bit


Disk devices formatted using traditional BIOS-based Master Boot Record (MBR) partitioning scheme are limited to a maximum disk size of approximately 2.2Tb and four primary partitions.
Whilst this size limit will be of minor concern when using smaller devices (<= 2Tb), it is problematic for larger devices where disk space beyond 2.2Tb will be inaccessible and unusable.
The UEFI-based GUID Partition Table (GPT) partitioning scheme supports a significantly greater device sizes and a limit of 128 partitions.
For these reasons, the use of GPT is increasingly preferred and necessary over the MBR partition table.

Through the use of a real-world example, this document describes how to convert the partition table of a disk from MBR to GPT.
This document primarily focuses on partition table conversion, although provides a complete example of related tasks for completeness.
The process described may similarly be used for other Linux releases using other filesystems types.
Additional information including various filesystem resize use cases are available from the references section below.


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In this Document
 1. Configuration Before
 2. Backup the filesystem
 3. Unmount the filesystem
 4. Perform filesystem check
 5. Convert device partition from MBR to GPT
 6. Verify partition table conversion from MBR to GPT
 7. Resize the partition
 8. Verify partition resize
 9. Resize the filesystem
 10. Verify filesystem resize
 11. Perform filesystem check
 12. Configuration After

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