DRBD refers to block devices designed as a building block to form high availability cluster. This is done by mirroring a whole block device via an assigned network. DRBD can be understood as network based RAID-1. (DRBD)

Sometimes we have a disk failure on hard drive which contains DRBD backing device. The following steps can be used to replace or recover the failed drive.

1. detach drbd resource from broken backing storage

# drbdadm detach <resource>

2. check state of drbd disk

# drbdadm dstate <resource>
Diskless/UpToDate

3. if using internal meta data, bind DRBD device to new hard disk

# drbdadm create-md <resource>
# drbdadm attach <resource>

4. if using external meta data DRBD unable to recognize hard drive was swapped, need additional step

# drbdadm create-md <resource>
# drbdadm attach <resource>
# drbdadm invalidate <resource>

Reference: http://www.drbd.org/users-guide-8.4/ch-troubleshooting.html