StorageIOblog

Will 6Gb SAS kill Fibre Channel?

With the advent of 6Gb SAS (Serial Attached SCSI) which doubles the speed from previous 3Gb along with other enhancements including longer cable distances up to 10m, does this mean that Fibre Channel will be threatened? Well, Im sure some conspiraicy theoritst or iSCSI die hards might jump up and down and say yes, finaly, even thogh some of the FCoE chearing section has already arranged a funeral or wake for FC even while Converged Enchanced Ethernet based Fibre Channel over Ethenret (FCoE) and its complete ecosystem completly evolves.

Needless to say, SAS will be in your future, it may not be as a host server to storage system interconnect, however look for SAS high performance drives to appear sometime in the not so distant future. While over time, Fibre Channel based high performance disk drives can be expected to give way to SAS based disks, similar to how Parralal SCSI or even IBM SSA drives gave way to FC disks, SAS as a server to storage system interconnect will at leat for the forseable future be more for smaller configations, direct connect storage for blade centers, two server clusters, extremly cost sensitive enviroments that do not need or can afford a more expensive iSCSI, NAS let alone an FC or FCoE based solution.

So while larger storage systems over time can be expected to support high performance 3.5″ and 2.5″ SAS disks to replace FC disks, those systems will be accessed via FCoE, FC, iSCSI or NAS while mid-range and entry level systems as they do today will see a mix of SAS, iSCSI, FC, NAS and in the future, some FCoE as well not to mention some InfiniBand based NAS or SRP for block access.

From an I/O virtualization (IOV) standpoint, keep an eye on what’s taking place with the PCI SIG and Single Root IOV and multi-root IOV from a server I/O and I/O virtualization standpoint.

Cheers
GS