Best Practice: Use Backup with your DRBD cluster!

We want to take an opportunity to explain LINBIT’s best practices in regards to DRBD and backup procedures.

DRBD is designed as a storage solution to provide High Availability, Disaster Recovery and Cross Site High Availability to your systems.  As developers of DRBD, we sometimes get community feedback that some folks are using DRBD as a “pseudo” backup solution, and in response to this we wanted to share some abstract guidelines on utilizing DRBD properly by following some key best practice methodologies.

Although DRBD is not backup software, it doesn’t mean you can’t use it in your backup procedures. Utilizing DRBD with LVM as a backing device, one can create backups with minimal to no interference to performance. This is done by utilizing LVM snapshotting as outlined in LINBIT’s DRBD User’s Guide.  Although this page outlines how to do snapshots before and after a resync, these could easily be adapted to a cron job.  Essentially one would disconnect the Secondary, snapshot the backing device, mount the snapshot, perform the backups, umount the snapshot, reconnect the Secondary.  These point in time backups are great for technology such as iSCSI targets, Virtual Machine storage or Databases such as MySQL and PostgreSQL.  As you can imagine, this methodology is quite popular in the Linux HA and DRBD communities.

LINBIT advises systems administrators to:

  1. Utilize DRBD for High Availability, Disaster Recovery and Cross Site High Availability (business continuity) purposes.
  2. Plan, review and execute a full backup strategy that makes sense for your organization and data.   Be sure to keep in mind how much data you’re planning on storing, backing up and at what intervals.  It is important to choose the point in time to make your backups to minimize things such as user error.  In many cases, backing up every day is the appropriate strategy.
  3. Test, test, test.  We cannot say this enough.We develop software that is designed to prevent loss from failure, so you could say we’re experts on this topic.  It’s very important that you not only test DRBD’s configuration, but the components that make up your backup system as well.  Then, on a scheduled basis, you should be reviewing your data to ensure its completeness and correctness.  As well, on an annual basis it would be wise to review your top level strategy and make updates if your requirements have changed.  In summation, it is advised to routinely test your backup procedure and also verify (checksum) your backups to ensure their completeness.

In closing, DRBD is designed to prevent loss of service as the result of equipment failure.  LINBIT strongly advises systems administrators to implement a strategy that incorporates “point in time” backups so administrators can restore, rewind and rejoice knowing that they’re not only backed by the best open source replication technology: DRBD, but a comprehensive backup solution that is designed for the organization’s needs in mind.

How do you backup your DRBD cluster?

Share your thoughts or comments below! 🙂

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devin
First introduced to Linux back in 1996, and using Linux almost exclusively by 2005, Devin has years of Linux administration and systems engineering under his belt. He has been deploying and improving clusters with LINBIT since 2011. When not at the keyboard, you can usually find Devin wrenching on an American motorcycle or down at one of the local bowling alleys.