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OCI Compute - Cannot Extend the Boot Volume of a CentOS 8 VM Instance (Doc ID 2967466.1)

Last updated on OCTOBER 30, 2023

Applies to:

OCI Compute - Version N/A and later
Information in this document applies to any platform.
This process applies to Compute Instances that are running CentOS 8.


When trying to extend the Boot Volume of an OCI Compute Instance that is having CentOS 8 as an OS image we may hit an issue where we are unable to extend its Boot Volume within the operating system.

The procedure for resizing a Boot Volume of a Linux-based Instance and then extending the partition of it to be visible within the OS is as follows:

  1. Resizing a Boot Volume using the Console as per Online Resizing of Block Volumes Using the Console or Offline Resizing of Block Volumes Using the Console.
  2. Rescanning the Disk for Volumes Attached to Linux-Based Instances ( only for using online resizing ).
  3. Extending the Root Partition on a Linux-Based Image using the "oci-growfs" operation from OCI Utilities.

After rescanning the disk with the following command:

And we will see that the "sda" device is still at the initial size and also the "/dev/mapper/centosvolume-root" filesystem is at the same size.


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