DRBD

Resources

The information in this article is representative of former times and has been archived. It can be used for reference, but is most likely not appropriate for current usage. Generally, archived articles should not be edited.

DRBD (or Distributed Replicated Block Device) is a network block device that provides reliability when storing data across multiple network nodes.

From the kernel documentation:

DRBD is a shared-nothing, synchronously replicated block device. It is designed to serve as a building block for high availability clusters and in this context, is a "drop-in" replacement for shared storage. Simplistically, you could see it as a network RAID 1.

Installation

Kernel

KERNEL Enable CONFIG_BLK_DEV_DRBD in the kernel

Device Drivers --->  Block devices --->
<*>   DRBD Distributed Replicated Block Device support

Emerge

Install sys-cluster/drbd-utils:

root #emerge --ask sys-cluster/drbd-utils

This package installs the userland utilities to interact with, and control DRBD. Also known as drbdsetup and drbdadm.

Troubleshooting

Errors

"ERROR: unknown cs for drbd0 : BrokenPipe, Update/DUnknown"

This error means connection state has a problem, link needs fixing, or drbd version updating. Upstream states "we had some issues with discarding the first successful connection and getting in a connect/brokenpipe loop."

Run this command to extract useful information:

root #cat /proc/drbd