Learn how to resolve the LXD Error: “The storage pool is currently in use”. Our LXC/LXD Support team is here to help you with your questions and concerns.

LXD Error: The storage pool is currently in use | Solution

Did you know that the error message “The storage pool is currently in use” in LXD occurs when the storage pool you are trying to modify or delete is actively being utilized by running containers or virtual machines?

This restriction ensures data integrity but can temporarily halt operations. Here’s how to understand and resolve this issue.

The error usually appears as:

Error: The storage pool pool_name is currently in use

This message indicates that the storage pool is locked due to active usage, and no modifications or deletions can be made until it is released.

An Overview:

• Impacts of the Error
• How to Identify Which Containers Are Using the Storage Pool
• Causes and Fixes
• Prevention Strategies

Impacts of the Error

• We cannot delete, modify, or perform specific operations on the storage pool while it is in use.
• Operations like starting, stopping, or migrating containers relying on the storage pool may be disrupted.
• Forcefully modifying or deleting a storage pool while in use can result in data corruption or loss.

How to Identify Which Containers Are Using the Storage Pool

Identifying which containers, snapshots, or processes are utilizing the storage pool is a critical step in resolving the “storage pool is currently in use” error. We can follow these steps to pinpoint active usage:

• Run “lxc storage info pool_name” to get detailed information about the storage pool, including the containers and snapshots currently linked to it. Look for sections that list container usage or active processes.
• Use “lxc config show container_name” to check the storage pool a specific container is using. Focus on the root or storage configuration entries.
• Use “lxc snapshot list container_name” to view snapshots associated with a container. Snapshots linked to the pool may cause the lock.
• Run “ps aux | grep storage_pool_name” to find background processes accessing the storage pool. Terminate unnecessary processes, if safe to do so.

By systematically following these steps, you can accurately identify the resources locking your storage pool. Once we fix the error, we can opt to increase the storage pool size as well.

Causes and Fixes

1. Active Containers

Containers using the storage pool are still running.

Fix:

• Stop individual containers:

  lxc stop container_name

• Stop all running containers:

  lxc stop –all
• Check container statuses:

  lxc list

2. Pending Operations

Ongoing operations like snapshots or migrations are using the storage pool.

Fix:

• Check for active operations:

  lxc list
• Wait for operations to complete or cancel them manually if necessary.

3. Incorrect Pool Configuration

Misconfigured or corrupted storage pool.

Fix:

• Inspect the storage pool configuration:

  lxc storage show pool_name
• Back up data and recreate the storage pool if needed:

  lxc storage create pool_name driver [options]

4. Resource Locking by Other Processes

Background processes (e.g., backup scripts) are accessing the storage pool.

Fix: Identify and terminate unnecessary processes:

ps aux | grep process_name

5. ZFS Dataset Issues

Locks on ZFS datasets are preventing access.

Fix:

• List active datasets:

  zfs list
• Release locks or perform a ZFS import/export operation if necessary.

6. Improper Shutdown of LXD Daemon

A previous improper shutdown left resources locked.

Fix:
Restart the LXD service:

sudo systemctl restart lxd

For snap installations:

nap restart lxd

7. Cluster Configuration Issues

Misconfigurations in a clustered environment are causing resource contention.

Fix:

• Ensure consistent configurations across all nodes in the cluster.
• Synchronize storage pool settings on each node.

Prevention Strategies

• Stop unnecessary containers before performing maintenance on storage pools.
• Always shut down LXD and its containers gracefully to avoid resource locks.
• Minimize disruptions by performing changes during off-peak times.
• Protect critical data by creating backups before making significant changes to the storage pool.

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Conclusion

By understanding the causes and applying these fixes, we can easily resolve the “The storage pool is currently in use” error. Preventive measures will help us avoid similar issues in the future.

In brief, our Support Experts demonstrated how to resolve the LXD Error: “The storage pool is currently in use”.