It’s been a while since I wrote. I had just finished a 2-week stint in Melbourne, conducting 2 Data ONTAP classes and had a blast.
But after almost 3 1/2 months of doing little except teaching NetApp classes, the stint is ending. I wanted it that way, to take a break and also to take on a new challenge. I will be taking on a job with Hitachi Data Systems, going back to the industry that I have termed the “Wild, wild west”. After a 4 1/2-year hiatus, I think that industry still behaves the way it is .. brash, exclusive, rich! The oligarchy of the oilmen are still laughing their way to the banks. And it will be my job to sell storage (and cloud) solutions to them.
In my Netapp (and EMC) engagements in the past 6 months, I have seen the greater adoption of iSCSI over Fibre Channel, and many has predicted that 10Gigabit Ethernet will be the infliction point where iSCSI can finally stand shoulder-to-shoulder with Fibre Channel. After all, 10 Gigabit/sec is definitely faster than 8 Gigabit/sec Fibre Channel, right? WRONG! (I am perfectly aware there is a 16 Gigabit/sec Fibre Channel, but can’t you see I am trying to start an argument here?)
Delivering SCSI data load over iSCSI on 10 Gigabit/sec Ethernet does not necessarily mean that it would be faster than delivering the same payload over 8 Gigabit/sec Fibre Channel. This statement can be viewed in many different ways and hence the favourite IT reply would be … “It depends“.
I would leave this performance argument for another day but today we are going to talk about some of the key additions to supercharge 10 Gigabit Ethernet for data delivery in storage networking capacity. In addition, 10 Gigabit Ethernet is the primary transport for Fibre Channel over Ethernet (FCoE) and it is absolutely critical that 10 Gigabit Ethernet must be close to as reliable as Fibre Channel for data delivery in a storage network.
Ethernet is a non-deterministic protocol, and therefore, its delivery result is dependent on many factors. Likewise 10 Gigabit Ethernet has inherited part of that feature. The delivery of data over Ethernet can be lossy, i.e. packets can get lost and the upper layer application protocols will have to respond to detecte the dropped packets and to ensure lost packets are redelivered to complete the consignment. But delivering data in a storage network cannot be lossy and in most cases of SANs, the requirement is to have the data arrive in the sequence they were delivered. The SAN fabric (especially with the common services of Layer 3 of the FC protocol stack) and the deterministic nature of Fibre Channel protocol were the reasons many has relied on Fibre Channel SAN technology for more than a decade. How can 10 Gigabit Ethernet respond?