SMI Cluster Manager in High Availability
The SMI Cluster Manager supports an active and standby High Availability (HA) model, which consists of two Bare Metal nodes. One node runs as Active and the other one runs as Standby node.
The SMI Cluster Manager uses the Distributed Replicated Block Device (DRDB) to replicate data between these two nodes. The DRDB acts a networked RAID 1 and mirrors the data in real-time with continuous replication. The DRDB is placed in between the I/O stack (lower end) and file system (upper end) to provide transparency for the applications on the host.
The SMI Cluster Manager uses the Virtual Router Redundancy Protocol (VRRP) for providing high availability to the networks. The Keepalived configuration implements VRRP and uses it to deliver high availability among servers. In the event of an issue with the Active node, the SMI Cluster Manager HA uses Keepalived to provide fail-over redundancy.
Note | The SMI Cluster Manager HA solution is a simple configuration, which requires minimal configuration changes. However, the fail-over time is longer because of mounting only one DRDB at once. |