Storage Appliances

SCALABLE STORAGE ARCHITECTURES
Today’s servers and storage systems are made up of numbers of interconnected and interoperating elements – processors, caches, memories, I/O bridge chips and channel, rotating disks and tapes, Local (LAN), Wide area (WAN) and Storage Area Networks (LAN, WAN and SAN). Users get the information they need from their applications by the movement and processing of data between each of, and usually all of these elements. The response time experi enced by the user is directly determined by the rate of movement, or speed, of delivered data and the latency between each of the elements. The overall operations, stability and performance are dependent on the overall architecture, balance and compatibility between the elements.

System Fabric Works (SFW) development and system integration focus is to architect the scalability and balance of each of these elements in the deployed systems, infrastructures and applications to deliver the required user experience. Traditionally the processor(s), or CPUs, have been the primary engines of data movement, particularly into and out of memory. Recent experience has shown that individual processors and memory busses have become more and more difficult to scale up in speed and more and more energy consuming. The response has been to deploy many parallel processing CPUs (i.e. cores), multiple systems (i.e. clusters) and parallel, switched access (i.e. I/O) channels between processors, memories and storage to scale up performance, as well as to provide direct access wherever possible – i.e. Remote Direct Memory Access (RDMA).

SFW’s Storage Appliances are built to leverage the scalability of open source software, RDMA standards, commodity x86 processors, PCI Express and SAS/SATA/NVRAM/Flash storage technologies. SFW supplies and supports two industry standard I/O transport architectures for RDMA – Ethernet and InfiniBand – two operating systems (O/S) that employ these – Linux and Windows – and one open source software stack, “OpenFabrics”, that ties user application interfaces (APIs) through the O/S to the system, channel and transport hardware.

BENEFITS OF OPENFABRICS SOFTWARE AND APPLICATIONS INTERFACES
SFW distributes and supports the OpenFabrics Enterprise Distribution (OFED) with either Novell or RedHat Linux distributions. The OpenFabrics stack contains the drivers, the operating systems’ interfaces and the upper level protocols that enable OFED running on Linux on commodity x86 platforms to perform the roles of initiators for RDMA implementations of SAN fabrics and NAS networks. This means that existing and legacy applications running on clients and servers can benefit from reductions in CPU cycle demand and latency, as well as increased performance and scalability of RDMA fabrics/networks.

HOW SAN APPLICATIONS WORK WITH SYSTEMFABRICSTOR APPLIANCES
Traditional lower speed SANs use Fibre Channel fabrics and Host Bus Adapters (HBAs) the kernel level drivers and APIs that run over SANs utilize the legacy SCSI protocol and the disk subsystems are the “SCSI Targets”. In RDMA fabrics/networks this is the SCSI Remote Protocol (SRP). SFW supplies and supports an open source SRP Target in its Storage Appliances.

NAS APPLICATIONS AND THE NETWORK FILE SYSTEM (NFS)
Traditional IP networks can also be used for storage attachment (NAS) using Ethernet interfaces in the client and server/storage system. Again the kernel level drivers and APIs that implement NAS utilize the legacy SCSI protocol, where it is known as iSCSI and the disk subsystems are the “iSCSI Targets”. In RDMA fabrics/networks the iSCSI Protocol is known as iSER. SFW intends to supply and support an open source iSER Target in its Storage Appliances.