Skip to content

Distributed Replicated Block Device (DRBD) in Netezza

Distributed Replicated Block Device (DRBD) is a block device driver that can replicate disk, partition, blocks, etc across different Linus database hosts in a HA cluster environment. Here are some of the high-level details on how DRDB works in Netezza appliance.

  • Netezza uses DRBD to replicate /nz and /export/home mount points from active (primary) host to passive (secondary) host
  • Data on primary host is committed only when it is written to secondary host i.e. synchronous replication is used
  • Synchronous replication helps in avoiding data loss incase of failover
  • Read activity from above mount points always take place in active host
  • Never stop DRBD service until or unless recommended by Netezza support. NOTE: This can result in brain split. A condition when both the nodes will have different data image

How to check DRBD service ?

DRBD service status can be checked by using one of the below two methods:

  • Run “service drbd status” command in Unix host
  • Run “cat /proc/drbd” command in Unix host