Migrating Volumes in Catalogic vStor

Prerequisites

To be eligible for a transfer, both the volume and the Destination Pool must meet specific criteria:

  1. Destination Pool:

    • Must not be the same as the current volume pool.

    • Must be in an ONLINE state.

    • Must have sufficient space to accommodate the moved volume.

  2. Volume:

    • Must not be currently moving.

    • The type must be FILESYSTEM, MINIO, or LUN.

    • Must not be a clone, have relationships, shares, or child volumes.

    • If of type LUN, must not have Host Mappings.

Tip. If a Volume has Shares, Relationships, or Host Mappings, you will be prompted with an option to detach them all at once in the web interface. This option appears after a failed move attempt due to these conditions.

Migrating a volume using the vStor Web Interface

To migrate a volume using the vStor Web Interface:

  • In Storage, locate a volume you want to migrate.

  • Click More Actions (•••) and select Transfer to Different Pool.

  • Select Destination Pool and click Move.

Migrating a volume using vStor CLI

To migrate a volume using the vStor CLI, use the following command and specify the ID of your destination pool:

vstor volume update --move_to <pool_id>

Volume migration process

Creating a snapshot

  • If the Volume does not have any snapshots before the move, an initial snapshot named volume_move_base_snapshot_<32 random character UUID> is created.

  • The move can be queued once all pre-conditions are met and there is at least one snapshot on the Volume.

Restrictions during the migration process

During the migration, the following operations are restricted for the moved Volume and impacted pools:

  • Updating MINIO type Volume settings.

  • Locking the Volume.

  • Updating the Volume's auto-lock feature.

  • Resizing the Volume.

  • Creating child Volumes.

  • Mounting the Volume for Agentless File Restore in DPX.

  • Cloning the Volume.

  • Creating Shares, Relationships, and Host Mappings on the moving Volume.

  • Destroying or changing the state of the Pool from which the Volume is moving, as well as the destination Pool.

  • Moving one Volume to multiple Pools simultaneously is not allowed.

Tip. Multiple move procedures can be queued, but only two will be processed concurrently.

Space Reservation and Resilience

Space is reserved on the destination Pool immediately upon starting the move and is released upon completion, cancellation, or failure. If the move is paused, the reservation remains until the move is resumed or canceled.

If the system or vStor service is shut down or rebooted, moving procedures will automatically restart within fifteen minutes after the vStor service is initialized.

Stages of the Moving Procedure

The move consists of two stages, StageOne and StageTwo:

  • StageOne: The Volume remains mounted and can be written to via the host filesystem. This stage involves moving existing snapshots.

  • StageTwo: The Volume is unmounted, and a final snapshot is created to carry over data added after the start of the move.

The progress bar updates every thirty seconds, with the ETA being an approximation and subject to change based on host performance.

Pause and Cancellation

Pausing or canceling the move is possible, but there are protected periods when these actions cannot be taken:

  • Approximately 45-60 seconds after StageOne starts and before it finishes.

  • Approximately 45-60 seconds after StageTwo starts and before it finishes.

These periods may vary with host performance. If you're moving small volumes, the entire process might be complete without an opportunity to pause or cancel. However, you can schedule another move to return the volume to its original Pool.

Resuming a paused move starts the progress bar from zero, but the total data transferred is reduced by the amount already sent.

See also. For more details on best practices for backup storage, see Backup storage: Best Practices.

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