Home > Storage > PowerMax and VMAX > Data Protection > Dell PowerMax: Reliability, Availability, and Serviceability > Active-Active Architecture
PowerMax systems aggregate up to sixteen directors with fully shared connectivity, processing, memory, and storage capacity resources. Each pair of highly available directors is contained within a common shell as an engine. The directors operate in a truly symmetric active-active fashion delivering sub-controller fault isolation and component-level redundancy. Each director contains hot-pluggable I/O modules that provide frontend host connectivity, SRDF connectivity, and backend connectivity. Management modules on each director provide environmental monitoring and system management intercommunications to all other directors in the system. Each director also has its own redundant power and cooling subsystems.
Redundant internal fabric I/O modules on each director provide communication interconnection between all directors. This technology connects all directors in the system to provide a powerful form of redundancy and performance by allowing the directors to share resources and act as a single entity. Data behind one director can be accessed by any other director without performance considerations.
The memory modules on each director are collectively distributed as a unified global cache. Global cache/memory is accessible by all directors in the array. When a new write operation is committed to memory, the new data is immediately available to all processors within every engine. While the data is protected in memory, the processors on all directors can work autonomously on the new data to update a mirrored pair, send the update over an SRDF link, update a TimeFinder copy, report the current status of all events to the management software, and handle error detection and correction of a failed component. All tasks can occur simultaneously, without de-staging to the drives and re-staging to a separate region in memory.