Hardware high availability on M4002-001

Hardware architecture on the customer-provided rack IAS M4002-001 appliance is designed in such a way that a single component failure should not disrupt database availability in most cases.

Data protection and redundancy is managed by GPFS. IAS maintains two copies of persistent data in two different nodes and is capable of surviving a node failure as well as a drive loss. Due to the small number of nodes and drives, this arrangement can still achieve adequate resiliency comparable to FlashSystem Arrays in rack-mounted IAS. No dedicated hot spare drive is provided.

Although hardware itself as a system is functional with surviving nodes in the cluster, in M4002-001 appliance, a node (server) failure will cause Db2® Warehouse to fail and requires restart. Therefore, a node failure causes disruption in database operation.

The nodes use two M.2 drives in mirror for OS boot. These M.2 devices are not hot swappable. When any M.2 card needs replacement, the node needs to be shut down.

Network: The three nodes are directly attached to each other via non-redundant 25G Ethernet links. Ring Buffer settings ensure that connectivity is still maintained on a single link failure. However, system performance might degrade.