DirectOS

DirectOS handles all the storage management functions within the S2A system. In addition to core system and data management, DirectOS features unique hardware-accelerated capabilities such as the S2A DirectRAID scalable, high-performance data protection engine and SATAssure Plus , the S2A's intelligent system-level SATA data integrity and self-healing drive repair technology.

Evolved over eight generations of continuous S2A innovation, DirectOS is a unique, full-featured system management suite proven to deliver the highest degrees of throughput performance, information scalability and robust data protection. DirectOS features several industry-leading capabilities including:

DirectRAID Real-Time Data Protection Engine

DirectRAID is a scalable, high-performance, data protection engine. DirectRAID spreads data across multiple drives in the S2A system to gain performance while calculating error correcting information in real-time to maintain extreme reliability. Unlike conventional storage systems which suffer performance loss during write operations, DirectRAID is unique in its ability to operate at full system speed during both writes of data to the array and reads of data from the array. DirectRAID enables writes to the array to occur as fast as reads from it, and it continues to operate at full performance regardless of check, error, or failure conditions.

SATAssure Plus

SATAssure enables the S2A to manage very large pools of SATA storage while maintaining enterprise-class performance, reliability and data integrity. SATAssure validates the integrity of data on every read operation to protect against corruption that is left unchecked by SATA drives. When such corruption is detected, SATAssure repairs the data on-the-fly so that the host computers receive the correct information, and then repairs any faulty data on the drive.

In the event any drive becomes non-responsive, the S2A will automatically power cycle individual drives in an attempt to reset errors and avoid drive replacements. This self healing action is performed transparently--with no administrator action required and no access or performance loss to any host or application.

Dynamic Maid (D-MAID)

D-MAID allows drives to spin down after a user-defined inactivity period to save additional power and cooling costs - especially beneficial with the S2A capacity allocated for archive use. Differing from rigid, static, conventional MAID technologies that entirely power down both the spindles and electronics - creating extensive periods of latency when data is requested – D-MAID only powers down the disk platters where over 80% of power is consumed. With the S2A's drive electronics still awake, data can be accessed in seconds.

S2A Storage Virtualization

The S2A integrates multiple host ports and natively allows full access to the storage pool from any host port. When restricted access is desired, this feature allows the common data pool to be divided, and provides multiple levels of security and access control to each portion of the storage pool.

S2A Rebuild Journaling

The S2A continually monitors the performance of all drives it manages. If it detects anomalies, it begins keeping a journal of all writes to that drive and attempts recovery operations. If the drive is recovered, only a portion of it needs to be rebuilt using the journaled information. This dramatically reduces rebuild times compared to standard methods and is especially important with SATA, drives given their large capacities.

Real-Time Mode

Real Time Mode overcomes the uncertainty in drive response times by utilizing the S2A's real-time parity engine to provide data to the host computer even when portions of it are missing due to individual slow drive performance.

PowerLUN: Performance LUN Aggregation

DirectOS supports PowerLUN's, which are an expanded group of drives that span multiple drive tiers, with a tier being a parity group of ten drives. PowerLUNs allow performance and capacity to be aggregated to extremely high levels.