User's Manual

StorNext File System Tuning
Distributed LAN Client Vs. Legacy Network Attached Storage
24 StorNext File System Tuning Guide
•Performance
•Fault Tolerance
•Load Balancing
• Client Scalability
• Robustness and Stability
• Security Model Consistency
Performance DLC outperforms NFS and CIFS for single-stream I/O and provides higher
aggregate bandwidth. For inferior NFS client implementations, the
difference can be more than a factor of two. DLC also makes extremely
efficient use of multiple NICs (even for single streams,) whereas legacy
NAS protocols allow only a single NIC to be used. In addition, DLC
clients communicate directly with StorNext metadata controllers instead
of going through an intermediate server, thereby lowering IOP latency.
Fault tolerance DLC handles faults transparently, where possible. If an I/O is in progress
and a NIC fails, the I/O is retried on another NIC (if one is available). If a
Distributed LAN Server fails while an I/O is in flight, the I/O is retried on
another server (if one is running). When faults occur, applications
performing I/O will experience a delay but not an error, and no
administrative intervention is required to continue operation. These
fault tolerance features are automatic and require no configuration.
Load Balancing DLC automatically makes use of all available Distributed LAN Servers in
an active/active fashion, and evenly spreads I/O across them. If a server
goes down or one is added, the load balancing system automatically
adjusts to support the new configuration.
Client Scalability As the following table shows, DLC supports a significantly larger
number of clients than legacy NAS protocols: