Extreme Drive Management Technology
SATAssure, an intelligent and robust SATA RAID drive management technology is a core element of the S2A DirectOS operating system and is built natively into the S2A appliance. This SATA RAID designed system delivers enterprise-class data protection by making it possible to confidently deploy very large pools of SATA storage while maintaining data availability, reliability and full system performance.
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. Learn More »
Background: Silent Data Corruption
SATA drives are far less robust than enterprise-class drives. They use lower quality components, and many of the resiliency features found in enterprise-class drives are simply missing. Since SATA drive capacities are substantially larger, this leaves data at risk, even when protected by standard RAID algorithms.
SATA drives do not check data integrity upon reads like enterprise-class storage drives do, enabling data to either become corrupted on the media, or from a bit error in the data path, causing the drive to forward bad data to the host computer without being aware of it. In a standard RAID system, data is protected by parity that only reconstructs data when a drive fails. In these systems, silent data corruption can still be passed to the hosts.
On-the-Fly Read & Write Parity Checking
With SATAssure, data is checked on-the-fly in real-time on every read. Not only will bad data be detected, it will be modified in-flight so that the host receives only the correct data. Additionally, the data can be checked on the media and repaired if necessary, all without a performance hit, a delay in access and completely transparent to the user.
SATAssure also helps stabilize large pools of SATA drives by attempting multiple levels of drive recovery before failing a drive. When most SATA RAID systems see a problem on a drive, they immediately fail it and begin rebuilds. This causes the entire SATA raid array to lessen performance while the rebuild operation is happening, and with the large capacities and lower reliability of SATA drives, these rebuilds can take extensive periods of time to complete and occur frequently. SATAssure doesn't immediately fail a drive when it detects an anomaly. Rather, it will try to re-read the drive, repair the defect, or reset the drive to recover it without a full failure. While this is occurring, there is no performance hit, and in most cases, the drive can be successfully revived, eliminating the need for rebuilds.
Partial Drive Rebuild Capability
DirectOS can intelligently and accurately rebuild only the bad sectors on SATA disks to return the system to full health as fast as possible. Partial drive rebuild capability is especially important as users deploy TB-sized disk drives which have very long, full-drive rebuild times. Moreover, the tremendous backend bandwidth of the S2A appliance--up to 24 GB/s in the flagship S2A9900--coupled with the S2A DirectRAID hardware-accelerated parity calculation engine ensures that no single drive rebuild will impact system performance.
Real-Time DirectRAID 6 with Full Read & Write Performance
With our innovative DirectRAID 6 implementation, double disk RAID 6 protection does not result in lower performance--even when using cost-effective SATA technology. Unlike conventional systems that suffer severe write performance penalties when implementing n+2 protection, the S2A appliance derives enterprise performance from high-capacity SATA drives and delivers full double-disk protection without compromising I/O performance.
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.
- Data is safeguarded all the way back to the application
- Drives stay online longer, are repaired faster and full enterprise system performance is uncompromised
- Users can comfortably deploy cost-effective, scalable SATA RAID environments
- Business-critical data is protected without sacrificing availability, integrity or enterprise-level performance