High Availability

High availability (HA) is achieved by including redundant components that can assume the function of failed components in order to provide interruption-free access to data in the event of a server, port, cable, or physical disk failure.

DataCore Servers can be paired in an active-active HA configuration with enough ports to allow redundant paths between DataCore Servers, storage hosts (front-end) and physical disks (back-end). Physical disks in pools can also be mirrored. Adding additional redundant components provides additional fault tolerance in the SAN.

During normal operations, the DataCore Server with the preferred path fields I/O requests from hosts and writes are performed on that server first. The same write operations are transferred to the other server in the group to keep the mirror copy of the virtual disk synchronized in real-time.

Pre-Requisites for High Availability:

• Two DataCore Servers connected to each other over a LAN. Each server must have one or more Fibre Channel or iSCSI connections (direct or indirect) between them. Two connections are recommended for fault tolerance.
• The DataCore Servers must exist in a server group in order to exchange configuration information and mirror virtual disk data changes from one server to the other. See Establishing Server Groups.
• DataCore or other qualified multipathing or HA device drivers need to be installed on hosts to provide HA access to mirrored virtual disks provided by DataCore Servers. See Qualified Lists on the DataCore Technical Support Portal for qualified High Availability products.