Trends in Storage Subsystem Technologies Michael Joyce, Senior Director Mylex & OEM Storage Subsystems IBM

The Drive Interface Progression Ultra640 SCSI 640 MB/s Ultra SCSI Ultra2 SCSI Ultra160 SCSI Ultra320 SCSI 40 MB/s80 MB/s160 MB/s320 MB/s Parallel SCSI Fibre Channel Arbitrated Loop 640 MB/s Ultra SCSI Ultra2 SCSI Ultra160 SCSI Ultra320 SCSI 40 MB/s80 MB/s 100 MB/s 320 MB/s 200 MB/s400 MB/s

System Interface Progression MB/s2 GB/s133 MB/s266 MB/s1 GB/s PCI/ PCI-X 32-bit 33 MHz 64-bit 33 MHz 64-bit 66 MHz 64-bit 133 MHz 64-bit 266 MHz Fibre Channel 1 Gb/s2 Gb/s10 Gb/s

Multi-Node SAN N-Node, Switched Fibre, N-RAID Controllers, FC Switch RAID Ctlr Port 0Port 1 RAID Ctlr Port 0Port 1 FC HBA RAID Ctlr Port 0Port 1 RAID Ctlr Port 0Port 1 FC HBA

Early IB Deployment: First-order Network Focus Characteristics n IB used mainly to get I/O out of 1U front- end servers. n High-end servers may not have IB links n SANs and LANs co-exist with IB n IB-to-FC and IB-to-Ethernet bridges to interconnect IB to SANs and LANs... Front-end/ Web Servers High-end Servers RAID Subsystems IB Switch Internet LANFC SAN

Initial iSCSI Deployment Until security and traffic/ usage perceptions are overcome, iSCSI SANs and LANs/ WANs will be distinct networks. Storage Arrays Server NodesFC SAN Storage Arrays Server Nodes FC SAN Storage ArraysServer Nodes iSCSI IP Network

Trend Towards Fabric Interconnects n “Get off the Bus - Get on the Fabric!” n Gigabit speeds and shrinking device geometries make it difficult to sustain buses. –Point-to-point interconnects gaining ground. n Within storage controllers, the current interconnect continues to be PCI/ PCI-X n But, competing technologies are appearing... –RapidIO, HyperTransport™ (AMD), 3GIO (Intel)

Divergence in Interconnect Technologies n Historically, storage subsystems have presented disk-drive like interfaces to the host. –SCSI, Fibre Channel n Moving forward, system interconnects are becoming fabric oriented to address distance, reliability, manageability and other issues. –InfiniBand, iSCSI, 10 Gb Fibre Channel

… Divergence n On next Fibre Channel progression, interfaces diverge. –10 Gb for system, 4 Gb for drives n Serial ATA emerges as a viable drive interface for desktops and storage subsystems. RAID/ Storage controllers facilitate divergence between system and drive interfaces.

Local Bus) Peripheral Bus CPU Core RAID Logic Storage Protocol I/F Bridge UART I2C GPIO GPT PCI-X I/F … Lead to Integrated RAID

RAID Teaming Dual or Multiple PCI RAID Controllers plugged in the same system, share the same backend disk devices (through SCSI or FC drive enclosure(s)). Terminator Switch (SCSI) or FC Hub Disk Drives (JBOD) Dual ported Enclosure (SCSI or FC) Dual PCI RAID Controllers Host System

FlashCopy Background Copy Write Read Source Logical DriveTarget Logical Drive

Remote Mirroring

Data Siphon

In Summary n Serial ATA emerges as a common interface for desktop and server class drives. n System interconnects move towards iSCSI and InfiniBand with iSCSI appearing to be gaining momentum. n System-on-chip trends will drive towards integrated RAID devices, especially at the low end. n RAID functionality enhancements will continue providing increased data availability, mobility, and manageability