Easy Setup
Xsan Admin 2
Cluster File System
High Performance
MultiSAN
Spotlight
High Availability
Xsan 2 is designed for high availability, with features that make it well suited for mission-critical environments.
Metadata controller failover
Xsan uses one system connected to the SAN, called a metadata controller, to manage access to shared storage. If this system fails for any reason, Xsan picks another computer on the SAN to take over its role. Cascading metadata controller failover ensures that you can access your data as long as any system on your SAN is active.
Using Xsan Admin 2, you can define per-volume failover priorities and set which volumes are hosted by which metadata controllers. Sophisticated algorithms ensure that succession occurs properly, avoiding “split brain,” or multiple conflicting metadata controllers. Once the file system clients “elect” a new metadata controller, the failed system can be deactivated until the problem is resolved.
For high-volume, mission-critical production environments, you may want to dedicate a computer as a standby controller. Having a standby controller also enables you to update Xsan software without interrupting service to your users.
Fibre Channel multipathing
Apple’s Fibre Channel host bus adapters (HBAs) are dual-port or quad-port cards, providing every Mac desktop or Xserve system with two or four connections to the SAN. Fibre Channel multipathing takes advantage of multiple connections: If one Fibre Channel path fails, Xsan continues to use another for storage access — eliminating a potential single point of failure at the cabling layer.
All data paths from the client to the various storage volumes are discovered automatically based on load and availability. This provides two major benefits: Any failure is handled without affecting the user’s work, and all paths are load-balanced to ensure maximum performance and reliability.
File system journaling
Xsan is a journaled file system that can be recovered in seconds in the event of a catastrophic failure. Journal data includes a record of file system transactions, eliminating the need for time-consuming integrity checks after an unplanned shutdown of the entire network or the metadata controller. Your storage can be back online almost immediately.
