Verifying DRBD Resource File

Oct 13, 2025 by wbrum.org 57 views

Introduction

Disaster recovery (DR) is a critical component of any high-availability system. In this article, we will explore the process of adding tests for DR in Anvil!, a powerful tool for managing and automating IT infrastructure. We will walk through the steps of setting up DR, linking nodes and DR hosts, and protecting servers.

Setting Up DR

To set up DR in Anvil!, we need to follow these steps:

1. Show the List of Nodes and DR Hosts

First, we need to show the list of nodes and DR hosts using the anvil-manage-dr command:

# anvil-manage-dr --show

This will display the list of nodes and DR hosts, including their descriptions and linked DR hosts.

2. Link DR Host to Node

Next, we need to link the DR host to the node using the anvil-manage-dr command:

# anvil-manage-dr --dr-host an-a01dr01 --link --anvil an-anvil-01

This will link the DR host an-a01dr01 to the node an-anvil-01.

3. Grow DR's VG

We need to grow the DR's VG (volume group) using the anvil-manage-host command:

# anvil-manage-host --auto-grow-pv --confirm

This will grow the LVM physical volumes and resize the partition table to use the free space.

4. Link DR's VG to SG

We need to link the DR's VG to the SG (storage group) using the anvil-manage-storage-groups command:

# anvil-manage-storage-groups --anvil an-anvil-01 --group "Storage group 1" --add --member KE03fH-9jp2-szdN-LcnL-fAfw-lG1A-pCqMsC

This will add the DR's VG to the storage group.

5. Protect Server

Finally, we need to protect the server using the anvil-manage-dr command:

# anvil-manage-dr --server srv01-sql --protect --dr-host an-a01dr01 --Yes

This will protect the server srv01-sql and create a DRBD resource file.

Verifying DRBD Resource File

After running the anvil-manage-dr command, we need to verify that the DR host now exists in the DRBD resource file:

# cat /etc/drbd.d/srv01-sql.res | grep -A13 connection | grep -B2 -A11 an-a01dr01

This will display the DRBD resource file and verify that the DR host is linked to the node.

Testing DR

To test DR, we can use the anvil-watch-drbd command to monitor the DRBD resource file:

# anvil-watch-drbd

This will display the status of the DRBD resource file and verify that the DR host is connected.

Conclusion

In this article, we have walked through the steps of setting up DR in Anvil! and testing the DRBD resource file. We have also explored the process of linking nodes and DR hosts, growing the DR's VG, linking the DR's VG to the SG, and protecting servers. By following these steps, we can ensure that our DR setup is working correctly and that our servers are protected in the event of a disaster.

Future Work

In the future, we plan to explore the use of DRBD Proxy v4 and the undocumented feature of "proxy / long-throw". We also plan to add more tests for DR and improve the overall DR setup process.

References

Anvil! documentation: https://anvil.readthedocs.io/en/latest/
DRBD documentation: https://www.drbd.org/
DRBD Proxy v4 documentation: https://www.drbd.org/drbd-proxy/
Frequently Asked Questions (FAQs) for Disaster Recovery (DR) in Anvil! ====================================================================

Q: What is Disaster Recovery (DR) in Anvil!?

A: Disaster Recovery (DR) in Anvil! is a feature that allows you to set up a secondary site for your servers, which can be used in the event of a disaster or failure at the primary site.

Q: How do I set up DR in Anvil!?

A: To set up DR in Anvil!, you need to follow these steps:

Show the list of nodes and DR hosts using the anvil-manage-dr command.
Link the DR host to the node using the anvil-manage-dr command.
Grow the DR's VG (volume group) using the anvil-manage-host command.
Link the DR's VG to the SG (storage group) using the anvil-manage-storage-groups command.
Protect the server using the anvil-manage-dr command.

Q: What is the purpose of the DRBD resource file?

A: The DRBD resource file is used to configure the DRBD (Distributed Replicated Block Device) resource, which is responsible for replicating data between the primary and secondary sites.

Q: How do I verify that the DR host is linked to the node?

A: To verify that the DR host is linked to the node, you can use the anvil-watch-drbd command to monitor the DRBD resource file.

Q: What is the difference between "short-throw" and "sync" protocols?

A: The "short-throw" protocol is used for DRBD, while the "sync" protocol is used for DRBD Proxy v4. The "short-throw" protocol is faster but less reliable, while the "sync" protocol is more reliable but slower.

Q: Can I use DRBD Proxy v4 with Anvil!?

A: Yes, you can use DRBD Proxy v4 with Anvil!, but it is still an undocumented feature and may require additional configuration.

Q: What is the purpose of the "proxy / long-throw" feature?

A: The "proxy / long-throw" feature is used to set up a proxy server that can handle long-distance replication, which is useful for large-scale deployments.

Q: How do I troubleshoot DR issues in Anvil!?

A: To troubleshoot DR issues in Anvil!, you can use the anvil-watch-drbd command to monitor the DRBD resource file, and also check the Anvil! logs for any errors or warnings.

Q: Can I automate the DR setup process in Anvil!?

A: Yes, you can automate the DR setup process in Anvil! using scripts or Ansible playbooks.

Q: What are the best practices for setting up DR in Anvil!?

A: The best practices for setting up DR in Anvil! include:

Using a separate network for DR traffic
Configuring the DRBD resource file correctly
Verifying that the DR host is linked to the node
Monitoring the DRBD resource file using anvil-watch-drbd
Automating the DR setup process using scripts or Ansible playbooks

Conclusion

In this article, we have answered some frequently asked questions about Disaster Recovery (DR) in Anvil!. We hope that this article has been helpful in understanding the DR setup process in Anvil! and troubleshooting common issues. If you have any further questions, please don't hesitate to contact us.