How EBS volume can be increased and decreased?
AWS EBS volumes can be resized by modifying the volume either through the AWS Management Console, CLI, or API, followed by adjusting the file system on the instance.
Increasing EBS Volume Size
- Modify the EBS volume:
- Go to the AWS Management Console > EC2 > Volumes, select the target volume, and choose Modify Volume.
- Specify a larger size (in GiB), or change the volume type if desired, and confirm.
- Monitor the status: The volume state changes to
modifying, which may take several minutes depending on the current size. - Extend the file system: Once the volume resizing is completed, the operating system detect the new space:
- Linux: Use commands like
lsblkto verify the volume, thenresize2fs /dev/xvdf(for ext4) orxfs_growfs /mount_point(for XFS) to extend the filesystem. - Windows: Use the Disk Management tool to extend the volume or run
diskpartcommands.
- Confirm the volume and file system: Ensure the new capacity is reflected both at the OS level and in the AWS console.
AWS does not support direct reduction of EBS volume size; you must create a smaller volume and migrate the data:
- Create a snapshot of the existing volume via the AWS console or CLI.
- Create a new, smaller EBS volume from the snapshot. Ensure the new volume is sized appropriately smaller than the original volume while accommodating all data.
- Attach the new volume to the instance and mount it.
- Verify data integrity: Ensure all required data is available and consistent on the new volume.
- Replace the old volume: Detach the old volume and optionally delete it, then remount the new volume as needed.
- Instance type compatibility: Ensure your instance supports the resized volume type.
- I/O impact: Modifying volumes may have a minor performance impact; schedule during low activity periods if performance is critical.
- Snapshots and backups: Always snapshot data before attempting resizing or migrating volumes to prevent accidental data loss.
- Automatic resizing: AWS
Elastic Volumescan automatically adjust the size and IOPS without downtime, depending on your instance type and EBS volume type.
By following these steps, you can safely increase the size of an EBS volume directly or decrease it indirectly via snapshot and migration.
