Manage an existing filesystem

This topic describes how to enable Zesty Disk to manage an existing Btrfs filesystem on Amazon EC2 instances.

The procedure is simple and can be done from the AWS Management Console or with the AWS CLI.

Limitations

RAID types are not supported. Zesty Disk supports only single-mode Btrfs filesystems.

To check if a volume is formatted in single mode, run this command:

sudo btrfs filesystem df /mount/point

Ensure that in the output, all volumes are single. For example:

# sudo btrfs filesystem df /mount/point
Data, single: total=10.00GiB, used=5.36GiB
System, single: total=32.00MiB, used=16.00KiB
Metadata, single: total=1.00GiB, used=256.00MiB

Prerequisites

  • AWS permissions to create volume tags, either from the AWS Management Console or the AWS CLI

  • Root (or admin) access to the instance

To manage an existing Btrfs filesystem:

  1. Tag all EBS volumes in the filesystem, in either of the following ways:

    • Use the AWS Management Console:

      1. Go to EC2 > Elastic Block Store > Volumes.

      2. Select all volumes in the filesystem.

      3. Click Actions > Manage tags > Add tags.

      4. Type the tag values:

        • Key: ZestyDisk

        • Value: True

    • Use the AWS CLI:

      1. Run the following command:

        aws ec2 create-tags --resources <VOLUME_IDs> --tags Key=ZestyDisk,Value=True

        Where <VOLUME_IDs> is the space-separated IDs of all the volumes in the filesystem.

  2. Install the Zesty Disk Agent, as described in Install the Zesty Disk Agent on standalone instances.
    If the Agent is already installed, reinstall to ensure you have the latest version.

  3. Remove the filesystem entry from /etc/fstab:

    1. Locate the filesystem by its device name or UUID.

    2. Remove the filesystem from /etc/fstab.

When Zesty Disk detects the updated volume tags, it will begin managing the filesystem. This can take up to 2 hours.