1.2.20.6 Block Store VIPs

To facilitate high availability and load balancing, iSCSI initiators communicate with Exascale iSCSI targets by using virtual IP addresses (VIPs).

Each VIP is associated with an Exascale block store worker (BSW) and provides a reliable network endpoint for iSCSI initiators. If the BSW instance fails, then the VIP, and the workload it supports, dynamically relocates to a working BSW instance.

Each BSW instance can support multiple networks. If the iSCSI initiators reside outside the Exadata environment, then they must connect using the Exadata client network. However, if the iSCSI initiators are located on the Exadata compute nodes, then you can leverage the high-speed low-latency storage network.

For the sake of load balancing, Oracle recommends using four VIPs for each network on every BSW instance. Using this arrangement, if the BSW instance fails, then the VIPs, and their workload, are redistributed across the working instances.

For example, consider the situation where the iSCSI initiators exclusively reside outside the Exadata environment and you have an Exascale cluster with three BSW instances. In that case, Oracle recommends that you configure 12 block store VIPs located on the Exadata client network.

The Exascale system administrator usually configures all of the block store VIPs. After configuration, the VIPs are dynamically allocated to the BSW instances. There are no ongoing VIP management tasks. If required, an administrator can delete a VIP.