DRBD (distributed replicated block device) is a low-level high-availability technology for Linux that replicates a block device by sychronizing changes to a mirrored device on another server. It works well on commodity hardware with standard networking equipment. It can be used to build high-availability and redundancy into any Linux-based application at low cost. It is open-source and free software that is included in the Linux kernel as of 2.6.33.
DRBD can be used as part of a balanced high-availability strategy to insure against data loss and maintain a standby machine in case the primary server fails. Percona's consultants have years of experience installing and using DRBD, including performance tuning and troubleshooting. We have designed and implemented some of the largest mission-critical DRBD installations.
We can help you assess whether DRBD is the right choice for your functional and business needs. It is not appropriate for all situations, and we might suggest other technologies such as MySQL replication or MySQL Cluster instead of DRBD. The primary factors to consider are performance, cost, reliability, and failover time and characteristics (including cache warming, filesystem journal replay, and database recovery). For applications that absolutely cannot lose a committed transaction, one of our favorite techniques is to use DRBD to mirror the server's binary logs, which is less performance-critical than the full dataset. We are also fluent in the accompanying technologies, such as Heartbeat, Linux-HA, Pacemaker, Corosync, and other parts of the Linux high-availability stack.
We are full-stack experts, not limited only to DRBD, so we can give you objective advice about the full range of technologies available to meet your goals. And if you decide to use DRBD, you can be comfortable knowing that we can take you from concept to finished product, including exhaustive testing of your entire software and hardware stack to ensure that it really provides industrial-grade high availability when disaster strikes.
Give us a call for friendly, expert help in deciding whether DRBD is right for you. You can talk to an expert during the sales process.