Just to be clear, I'm not arguing that FC isn't a more efficient protocol than Ethernet -- in fact, I think I said as much already.
All I'm saying is that in the real world, 10Gb Ethernet NAS can perform as well as 8Gb FC SAN. There are trade-offs for everything. An Ethernet network can be cheaper and easier to manage, while an FC network can be more efficient (which *may* perform better) and be more secure. -Adam On Sat, Apr 5, 2014 at 4:26 PM, Skylar Thompson <[email protected]>wrote: > On 04/05/2014 12:59 PM, Edward Ned Harvey (lopser) wrote: > >> From: [email protected] [mailto:discuss- > >> [email protected]] On Behalf Of Adam Levin > >> > >> 2) It used to be the case that 1Gb Ethernet, even using LACP or other > >> aggregation protocols, couldn't keep up with FC. FC is a more efficient > >> protocol than NFS. However, now that we have 10Gb Ethernet, it's > really no > >> longer an issue. > > > > I disagree bigtime. Even if you run iscsi over 10Ge, it still has to go > through all the mac/ip/application layers, not to mention, the 10Ge switch, > probably buffering, store and forward, etc. If you have a network such as > Infiniband or Fibre Channel, you're able to skip all those and use DMA > directly, which greatly decreases latency. Also, the speed of even the > slowest IB network is around 40 Gbit, while ether maxes out at 10Gbit. > > > > Whether using SSD or HDD, the sustainable throughput of each individual > device is around 1Gbit. So the max performance of a 10Ge network is on-par > with 10 disks. Which would be a pathetically small SAN. > > Agreed. FC also has the benefit of preventing over-subscription of a > channel by design - you might saturate a link but you won't experience > dropped frames. FC channel aggregation blows the socks off LACP as well; > the usage on each individual channel is far more uniform than with LACP > since an incoming are sent to the first channel with available credits > rather than using some arbitrary hashing algorithm. > > Skylar > _______________________________________________ > Discuss mailing list > [email protected] > https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss > This list provided by the League of Professional System Administrators > http://lopsa.org/ >
_______________________________________________ Discuss mailing list [email protected] https://lists.lopsa.org/cgi-bin/mailman/listinfo/discuss This list provided by the League of Professional System Administrators http://lopsa.org/
