Increasing the size of an AWS disk volume

Last Updated : Jun 05, 2026 |

About this task

Use this procedure to add additional storage to the system by increasing the size of an attached disk and then allocating the free space to volumes on the disk. You cannot decrease the size of a disk.

Procedure

  1. On the Amazon Web Services console, navigate to Services > Compute, and then click EC2.
  2. On the EC2 Management Console page, click Instances.
  3. Select the instance to which you want to add storage.

    The system displays instance details.

  4. Click the Description tab.
  5. In the Block devices field, select a disk for which you want to increase the size:

    The options are:

    • disk1

    • disk2

    • disk3

    • disk4

    For more information about disk options, see Block device descriptions.

  6. In the EBS ID field, click the ID.

    The system displays the Volumes page with only the selected device.

  7. To update the storage on the EBS disk volume, click Actions > Modify Volume.
  8. In the Modify Volume window, in the Size field, enter the required disk size.
  9. Click Modify.
  10. In the Confirmation window, click Yes.
  11. In the status window, click Close.
  12. Log in to the system using the SSH console or PuTTY.
  13. Required If you added storage to disk1, restart the system for the changes to take effect.

    A restart is not required when increasing the size of the other disks.

  14. To use the newly allocated space, update the file system by running the following commands:
    1. sys volmgt --summary: To view the current disk space allocation for each volume.

      The order of block devices shown on the EC2 management console might not match the order of the devices shown in the summary tool output. Reference the devices by name and not by their display order.

    2. sys volmgt --scan: To scan the disks for newly allocated space.
      Important:

      If prompted, restart your system before continuing.

    3. sys volmgt --extend [ <n>m | <n>g | <n>t | --remaining ]: To assign unallocated disk space to the volumes on a disk, specifying the amount of space you want to add to each volume. Repeat this step for each volume that you want to extend.

      For example, to extend the size of the /var/log/Avaya volume on disk1 by 10 GiB, run the \sys volmgt --extend /var/log/Avaya 10g command.

      For more information, run the sys volmgt --hhelp command.

    4. sys volmgt --summary: To review the disk space allocation for each volume after the changes are made.