Author: David So, Strategic Marketing Manager,
The storage industry has gradually been introduced to the newest storage interface, Serial Attached SCSI (SAS), over the past few years. In that time, numerous companies have announced a wide array of SAS infrastructure components as well as SAS-based servers and external storage systems. Among those companies are SCSI Trade Association (STA) members LSI Logic, Adaptec, Fujitsu, Hitachi GST, HP, Intel, Molex, PMC-Sierra, Seagate, and Vitesse, with products including ICs, host bus adapters (HBAs), cables, 2.5″ and 3.5″ disk drives and drive enclosures.
STA has gone to great lengths to educate the public on the features and benefits of SAS and why this technology will be critical to the future of Direct Attached Storage (DAS) environments, and potentially Storage Area Networks (SANs). STA has sponsored a series of plugfests at the University of New Hampshire’s InterOperability Lab to ensure compatibility of different vendors’ SAS products with one another, thereby easing the adoption and integration of SAS into the marketplace.
With the performance, scalability, and flexibility benefits that SAS offers, not only beyond its predecessor SCSI, but also beyond other storage interfaces available today, it is easy to understand why SAS is being accepted and adopted readily as the next generation of the ubiquitous SCSI interface. The demands on enterprise data centers worldwide are ever-increasing, with the need for greater amounts of storage (think Sarbanes-Oxley and HIPAA as two examples) and higher performance, all at price parity (at least) with previous generations of technology. In addition, there is the desire for lower power consumption plus the greater restrictions on space within the data center. Add all of these components together and the answer you get is SAS.
SAS ICs, HBAs and RAID Adapters
LSI Logic offers a broad range of SAS solutions in the industry, ranging from controller and expander ICs, to HBAs and RAID adapters, to external storage. LSI was the first to introduce PCI-X-to-SAS controller ICs to the market, with both 4- and 8-port SAS versions – the SAS1064 and SAS1068, respectively. Those were followed by the industry’s first production PCI Express-to-SAS controllers, the 4-port SAS1064E and the 8-port SAS1068E, in early 2006. Providing unprecedented performance and scalability for server DAS and external storage system environments, these SAS controller ICs meet the increasing bandwidth and flexibility demands of blade server environments and high-end server and storage subsystems.
Expanders are critical to the scalability of SAS topologies, allowing creation of SAS domains with more than 16K end-devices. LSI offers 12-port, 28-port, and 36-port expander ICs. The 28-port SASx28 and 36-port SASx36 expanders support SAS zoning for storage partitioning and incorporate an ARM processor that can be used for enclosure management as well as extended SAS SMP functions. Much like the controller ICs, each expander IC supports 3Gb/s SAS and SATA data transfers per port, SAS and SATA drive connectivity, and wide-port support for aggregated bandwidth across multiple SAS phys.
Figure 1: LSI Logic SAS Product Portfolio
LSI’s family of SAS HBAs (based on the controller ICs mentioned above) are available with PCI-X and PCI Express host interfaces and four- and eight-port SAS connections, with a wide variety of internal and external connector options to support any application or system topology. Many of these HBAs support LSI’s Integrated RAID (IR), a highly-integrated, hardware-based RAID solution ideal for systems requiring redundancy and high availability, but not needing a full-featured RAID implementation. IR includes Integrated Mirroring and Integrated Striping for support of up to eight physical disk drives. The table below shows some of the production LSI HBAs and their various SAS connector offerings.
LSI also has a full line of MegaRAID® SAS adapters featuring external and internal storage connectivity and delivering high-performance, flexible, fault-tolerant data protection that is scalable for both SAS and Serial ATA (SATA) configurations. The newest additions to this family are the low-profile 8-port internal MegaRAID SAS 8708ELP and the low-profile MegaRAID SAS 8888ELP adapters, both based on LSI’s proven SAS1078 PCI Express to 8-port SAS RAID-on-a-Chip (ROC) IC. With selectable connectors, the 8888ELP serves multiple deployment needs. Users may select one of three connector configurations: two internal, two external or one of each. Both adapters offer 3Gb/s throughput per port, the ability to intermix SAS and SATA devices in the same array plus support for SAS expanders and SATA native command queuing (NCQ).
Additionally, each adapter provides RAID 6 support to protect against data loss in the event of dual-drive failures. This is a critical feature in SAS environments where systems are often deployed with higher capacity, yet lower reliability SATA drives. The MegaRAID SAS 8708ELP and 8888ELP adapters also offer battery backup options to protect the integrity of cached data. By providing power in the event of a brief power outage or complete AC power failure, MegaRAID battery backup units provide an inexpensive alternative to using an uninterruptible power supply.
These second-generation MegaRAID SAS cards are supported by the MegaRAID Management Suite™ of software, which provides a complete spectrum of applications and tools including next generation pre-boot and advanced online RAID management utilities. This suite of applications features a variety of configuration options and SAS topology views from the system host, controller, and disk enclosure down to the logical and physical drive level. This allows administrators to efficiently configure, monitor, and manage volumes of RAID locally or over the network.
SAS Storage Systems
LSI recently announced its first SAS-based external storage systems, the Engenio 1333 and 1331, featuring SAS-to-SAS external RAID arrays for shared DAS infrastructure. The model 1331 and 1333 systems feature a modular design that creates an affordable entry point without sacrificing future scalability, enabling configured system capacity to be easily matched to initial amounts of storage needed and scaled up as storage requirements grow. Dual-active controllers with up to 12 drives in a 2U enclosure create a fully featured and reliable storage system. And when capacity and/or functionality requirements change, the 1333 supports up to 36 additional drives and offers key-enabled features for additional functionality.
Multi-port model 1333 is an ideal entry-level solution for clustered topologies and readily meets end-users’ external two-node clustering requirements. Clustering allows multiple servers to share access to data stored on a single storage system and keeps applications running on a secondary server should the primary server fail.
The new systems enable growing businesses to reap the benefits of shared storage including consolidation, unified management, data protection features and increased efficiencies within the IT infrastructure. Managed by Simplicity Storage Manager software, the systems bring an intuitive, task-based management structure that significantly reduces the complexity of installation, configuration, management, and diagnostic tasks, along with feature-rich capabilities to enable deployment of advanced data protection strategies.
LSI offers a very broad portfolio of SAS storage solutions, addressing every segment of the market. By offering best-of-breed SAS technologies, assured interoperability and single vendor support, LSI is the silicon-to-systems supplier of choice for many OEMs and SMBs who require a broad set of storage solutions.
For more information about LSI Logic Serial Attached SCSI products, please visit www.lsi.com/storage_home/products_home/.