Intel Announces Open Fibre Channel Over Ethernet

sofar writes "Intel has just announced and released source code for their Open-FCoE project, which creates a transport allowing native Fibre Channel frames to travel over ordinary ethernet cables to any Linux system. This extremely interesting development will mean that data centers can lower costs and maintenance by reducing the amount of Fibre Channel equipment and cabling while still enjoying its benefits and performance. The new standard is backed by Cisco, Sun, IBM, EMC, Emulex, and a variety of others working in the storage field. The timing of this announcement comes as no surprise given the uptake of 10-Gb Ethernet in the data center."

Fiber channel

[smitty_one_each (243267)]

Fiber channel
In ye olde patch panel
Beats fiber thin
On your chinny-chin-chin
Burma Shave

Speed?

[Chrisq (894406)]

As far as I can see this is a way of bridging fibre channels over Ethernet. This does not necessarily mean that you will get fibre-like speed (throughput or latency). I am sure that this will have some use, but it does not mean that high performance data-centres will just be able to use Ethernet instead of fibre.

Re:

[farkus888 (1103903)]

I am not too sure about the latency, but I don't know of any storage solution that can saturate 10 Gb sustained speeds. except maybe something like gigabytes array of ram as a hd system. simply reducing the number of drives on a daisy chain should keep you running happily as far as throughput goes.

Re:

[afidel (530433)]

Huh? Our piddly 150 spindle SAN could keep a 10Gb link saturated no problem if we had a workload that needed it. In fact that's less than 7MB/s per drive, about one tenth of what these drives are capable of for bulk reads or about one fifth for bulk writes. Even for totally random I/O 150 spindles could probably keep that sized pipe filled.

Re:

[farkus888 (1103903)]

I didn't think anyone intended this for the main pipes of a SAN. I thought it was for bringing those individual spindles back the the FC switch. then using fiber for the big links. though to be honest my understanding of FC SANs is poor, I am honestly posting more to get someone to explain it to me because I said something wrong than to try to enlighten others.

Re:

[afidel (530433)]

Nah I see this as a lower cost way to distribute from the FC switch back to the storage users eg the servers. Most storage is also presented by some kind of storage array, very very little is JBOD presented directly by a switch. This is mostly due to the lack of management of JBOD as well as the fact that the performance improvement of placing a bunch of intelligent cache in front of the storage pool is huge.

Re:

[Intron (870560)]

No big company wants to maintain two separate optical fiber networks, so you either get ethernet or fibre channel for your long runs. Since it's inception, you have been able to run ethernet over fibre channel, but almost nobody uses expensive (FC) technology when they can use cheap technology (ethernet). Alternatively, you can run iSCSI which is serial SCSI over ethernet. FCoE lets you bridge two remote fibre channel SANs or connect to remote fibre channel storage using ethernet without having to conver

Re:

[shaggy43 (21472)]

I have an account that I support that has completely saturated 4 4G ISL's in-between 2 Brocade 48k's, and had to re-balance their fibre. Granted, and individual HBA doesn't hit a sustained 2G/sec, but 16G/sec saturated to a pair of HDS Thunders is impressive.

Mostly, I think this technology will compete against iSCSI, not dedicated fibre, with all the drawbacks -- plus an added drawback of currently being single-platform.

Re:Speed?

[afidel (530433)]

According to this netapp paper [netapp.com] even NFS over 10GbE is lower latency than 4Gb FC. I imagine if the processing overhead isn't too high or offload cards become available then this would be significantly faster than 4Gb FC. As far as bandwidth 10>4 even with the overhead of ethernet framing, especially if you can stand the latency of packing two or more FC frames into an ethernet jumbo frames.

Re:Speed?

[Intron (870560)]

Umm. The paper says that the test load was sequential reads entirely cached in memory, so not exactly an unbiased test.

Re:

[Phishcast (673016)]

Just thought I'd point out that NFS (NAS) is NetApp's bread and butter. They've been saying NFS is as good as block storage over Fibre Channel forever, and not everyone agrees. Their claim may or may not be true, but this coming from NetApp should be scrutinized in the same way as a statement from Microsoft saying how much lower their TCO is compared to Linux. Storage vendors are well skilled at spin.

Re:

[saleenS281 (859657)]

8Gb FC will be out long before 10Gb ethernet becomes reasonably priced.

Re:

[Znork (31774)]

"8Gb FC will be out long before 10Gb ethernet becomes reasonably priced."

You mean, 8Gb FC will be out long before 100 Gb ethernet becomes reasonably priced.

10 Gb ethernet is already reasonably priced (compared to FC).

Re:

[afidel (530433)]

10GbE is reasonable today. Quadrics has a 96 port switch for only $300 per port and adapters are only $1K (eg NC510C from HP or the PXLA8591CX4 from Intel). Sure you can get 2Gb FC for around this same price point but 4Gb is significantly more. Brocade wants $500 per port with no SFP's and only 32 of the 64 ports enabled for the Silkwork 4900, fully configured you're at greater than $1,500 per port. Qlogic is similar for the SANbox 9000.

Re:

[Chris Snook (872473)]

Why not? Switched fabric topology has no inherent latency benefit over star topology, and the majority of servers in a data center aren't doing anything that need any more sophisticated throughput aggregation than 802.3ad (LACP) bonding will give you. As long as you have pause frame support (a prerequisite for this FCoE implementation) you can create a lossless ethernet network, which eliminates the need for much of the protocol overhead of something like iSCSI, as long as you're staying on the LAN.

FCoE s

Re:

[complete loony (663508)]

Whatever happened to ATAoE? Wasn't that supposed to be the cheap equivalent to iSCSI / Fibre Channel?

More to the point, how difficult and expensive would it be to build a chip to interface between FCoE and a SATA drive?

I'm still hoping for a cheap consumer solution for attaching drives directly to the network.

Re:

[jabuzz (182671)]

Want to represent your tape drive using AoE? Sorry you are out of luck. FCoE offers all the benefits of AoE (i.e. using cheap Ethernet, with no TCP/IP overhead) but the flexibity to do stuff other than SATA drives.

Re:

[jcnnghm (538570)]

We have a SR1521 [coraid.com], and it seems to do its job pretty well. It provides lots (over 7TB) of cheap storage space to the network. It probably isn't as fast as some other solutions, but our application doesn't need it to be.

Re:

[jsailor (255868)]

For that type of project, look to the hedge fund community. I know of 2 hedge funds that have built their own storage systems that way - Ethernet, Linux, direct attached disk, and a lot of custom code. My world doesn't allow me to get into the details, so I can't elaborate. My only point is that their are folks doing this and it tends to be the guys with large storage needs, moderate budgets, and a great deal of freedom from corporate standards and vendor influence.

Re:

[canuck57 (662392)]

My only point is that their are folks doing this and it tends to be the guys with large storage needs, moderate budgets, and a great deal of freedom from corporate standards and vendor influence.

Stay with them, these are good environments. BTW, I am not anti-standards, but at the end of the day they need to make sense. That is, not a standard for pure political posturing.

10GE is a heck of a lot cheaper

[afidel (530433)]

As long as a server is within the distance limit of copper, 10GE is about 3-4x cheaper then even 2Gb FC. We've also had a heck of a lot more stability out of our 6500 series switches then we have out of our 9140's and the 9500's are extremely expensive if you have a need for under 3 cards worth of ports.

High End customers will not go to this.

[BrianHursey (738430)]

As we have seen with iSCSI the bandwidth capability over Ethernet just is not there. I with the EMC this will probably be great for the low end company that needs a mid tier and low tier environment. However large corporations with large database and high number of systems still need to stay with fibre frabrics. This probably will be only on the mid tier platforms like clariion.

Re:High End customers will not go to this.

[totally bogus dude (1040246)]

I expect you're right, but it's interesting to note they're referring to this as Fibre Channel over Ethernet, and not over IP. The reduction in overhead there (not just packet size, but avoiding the whole IP stack) might be enough to really help; and if you're running separate 10 Gigabit Ethernet for the storage subsystem (i.e. not piggy backing on an existing IP network) it might be really nice. Or at least, comparable in performance and a heck of a lot cheaper.

On the other hand, really decent switches that can cope with heavy usage of 10-GigE without delaying packets at all aren't going to be massively cheap, and you'd need very high quality NICs in all the servers as well. Even then, fibre's still probably going to be faster than copper... but that's just something I made up. Maybe someone who knows more about the intricacies of transmitting data over each can enlighten us all?

There was recently an article about "storing" data within fibre as sound rather than converting it to for storage in electrical components, since the latter is kind of slow; how does this compare to transmission via current over copper?

Re:High End customers will not go to this.

[afidel (530433)]

Latency and bandwidth are comparable for copper and fiber ethernet solutions today, the drawback to copper is you need to be within 15m of the switch. This isn't so bad in a small datacenter but in a larger facility you would either need switches all over the place (preferably in 2's for redundant path) or you'd need to go fiber which eliminates a good percentage of the cost savings. FiberChannel used to have copper as a low cost option but it's not there in the 4Gb world and even in the 2Gb space it was so exotic that there was almost no cost savings due to lack of economies of scale.

Re:

[guruevi (827432)]

FibreChannel has a lot of copper in a lot of installations, all you need to do is get an SFP module that terminates copper instead of fiber optics. Especially for direct connects between servers and storage (Apple XRAID and Dell solutions for example) or direct connects between switches and storage in the same rack. The interconnects for large SAN's (between switches and backbones) are usually fiber though. Fiber is very expensive and the SFP's themselves are not cheap as well neither are the switches any c

Re:

[eth1 (94901)]

My company has several large data centers. While the network portion is generally separated from the server portion, so that two servers next to each other in a rack might talk to each other via a switch 25m away, the SAN racks and the servers that use them are usually fairly close to each other. There's no reason why an off-net storage switch couldn't be located in the SAN rack and connected directly for most installations.

Granted, you do lose some placement flexibility, which might be a deal-breaker in so

Re:

[teknopurge (199509)]

(4) bonded NICs/server
(1) Procurve gigE switch w/Jumbo frames turned on
(many) SAS drives

and we can, in production, have 4Gb throughput on our iSCSI SAN.

Tell me again where this "throughput" is hiding?

Regards,

Re:High End customers will not go to this.

[Chris Snook (872473)]

Bullshit.

The bandwidth is there. I can get 960 Mb/s sustained application-layer throughput out of a gigabit ethernet connection. When you have pause frame support and managed layer 3 switches, you can strip away the protocol overhead of iSCSI, and keep the reliability and flexibility in a typical data center.

The goal of this project is not to replace fibre channel fabrics, but rather to extend them. For every large database server at your High End customer, there are dozens of smaller boxes that would greatly benefit from centralized disk storage, but for which the cost of conventional FC would negate the benefit. As you've noted, iSCSI isn't always a suitable option.

You're probably right that people won't use this a whole lot to connect to super-high-end disk arrays, but once you hook up an FCoE bridge to your network, you have the flexibility to do whatever you want with it. In some cases, the cost benefit of 10Gb ethernet vs. 2x 4Gb FC alone will be enough motivation to use it even for very high-end work.

Re:

[Chris Snook (872473)]

Oops, I was vague. My results were with UDP NFS, which is much simpler to tune. As you noted in your reply, it's possible to tune iSCSI to similar performance levels, but doing so without sacrificing latency is rather difficult. My point was that simpler protocols (like FCoE) make it much easier to get the most out of the hardware.

For what it's worth, the NFS server in my testing was using Fibre Channel storage.

Re:

[Znork (31774)]

I max out at 960Mb/s with iSCSI over gigabit $15 realtek cards with a $150 dlink switch. With out of the box iSCSI enterprise target software on Linux, to a client running OpeniSCSI (eh, or whatever it is that's shipped in RedHat by default). Over substandard cabling, on top of that. (Fer sure, by then the iSCSI server has cached the data in-mem, but anyway.)

So I'd really have to wonder what anyone failing to get that is running. I hope they're not paying for it.

Sure, non-cached performance against the IDE

Re:

[myz24 (256948)]

I think you could follow up with some info about your setup. I mean, there is no way you're getting those speeds without tuning some network parameters or with some serious CPU and RAID setup. It's not that I don't believe you, I have a buddy that has done the same but with NFS but he's using an opensolaris system with TCP offloading cards and a heck of a RAID array.

Re:

[Znork (31774)]

"those speeds without tuning some network parameters or with some serious CPU and RAID setup."

Basic setup is approximately this; CPU's for both servers and clients range between AMD XP 3500+ to AMD X2 4800+. Motherboards are Asus (Nvidia 550 and AMD690) cards, with 2-4GB memory plus an extra SATA card on the iSCSI servers, and extra rtl8168/9 gigabit cards (the forcedeth driver has some issues). Disks on the iSCSI servers are striped with LVM, but not to more than 3 spindles (I dont care that much about max

Srsly, FC or iSCSI?

[smcdow (114828)]

I'm not a datacenter kind of guy, so help me out. If you've got 10 G Ethernet, then why would you want to run FC rather than iSCSI?

Can someone elaborate?

Re:

[cerelib (903469)]

Here is the simple version.

iSCSI is for implementing a "direct attached storage device" using an IP network (Internet/internet/intranet) as the backbone.

FCoE does not involve IP and is simply a lower cost, possibly better (time will tell), way of replacing optical fabric in data centers.

Re:

[Chris Snook (872473)]

iSCSI adds a lot of protocol overhead, and tuning it to work well with a given application and network load becomes quite difficult above gigabit speed. When you're using a fairly reliable transport, such as FC or Ethernet with pause frames, you can dispense with that, and get near-optimal throughput and latency with very little tuning.

Re:

[Vellmont (569020)]

I'm not a datacenter kind of guy, so help me out. If you've got 10 G Ethernet, then why would you want to run FC rather than iSCSI?

I'm not a datacenter guy either, but I am a programmer.

My guess is simply just avoiding the IP stack. I'd guess an IP stack would add some latency, definitely adds some overhead, and most implementations are unlikely to be well optimized for extremely high bandwidth links (10 Gbit/sec).

FCoE avoids the IP stack entirely. If done properly, it can avoid all of the above problems.

Re:

[Slashcrap (869349)]

Okay now I'm confused. If you're avoiding the IP stack entirely, where does crossing subnets come into play?

I guess they'll just have to cross that bridge when they come to it.

Re:

[Joe_NoOne (48818)]

Some important limitations of iSCSI :

1) TCP/IP doesn't guarantee in-order delivery of packets (think of stuttering with streaming media, etc...)

2) Frame sizes are smaller and have more overhead than Fibre Channel packets.

3) Most NICs rely on the system to encapsulate & process packets - a smart NIC [TCP Ofload Engine card] costs almost as much as a Fibre Channel card.

Re:

[onemorechip (816444)]

It doesn't *deliver* packets in order (at least, not unless the underlying network does). It provides the capability to reconstruct the original order. GP was talking about *delivery* of packets.

Re:

[Znork (31774)]

Well, basically, this is how it works:

Yer olde FC product salesman has a much better commission, as FC products have far, far higher margins than ethernet products. Therefore the FC saleman buys you better lunches and invites you to seminars with more free booze, while displaying his company produced graphs over how cutting edge lab FC hardware vastly outperforms iSCSI served by a PC from last century.

In your booze addled state you find this reasonable, and refrain from using google or performing actual tes

Too late: I'm already using AoE

[Tracy Reed (3563)]

AoE is awesome, it is cheap, it is simple. 8 page RFC. The only SAN protocol you can really understand completely in one sitting.

http://en.wikipedia.org/wiki/ATA_over_Ethernet [wikipedia.org]

And combine it with Xen or other virtualization technology and you have a really slick setup:

http://xenaoe.org/ [xenaoe.org]

Re:Bumper cars.

[morgan_greywolf (835522)]

Oh this should be interesting. Fibre over a collision-and hold-off architecture.

They have this newfanged technology. It's called switched Ethernet! It's amazing! With switched Ethernet, you get no collisions!

eth0 Link encap:Ethernet HWaddr 00:00:0D:03:01:04
                    inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
                    inet6 addr: fe80::000:00f0:0043:0084/64 Scope:Link
                    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
                    RX packets:1781638 errors:0 dropped:0 overruns:0 frame:0
                    TX packets:1651683 errors:0 dropped:0 overruns:0 carrier:0
                    collisions:0 txqueuelen:1000
                    RX bytes:803882935 (766.6 MiB) TX bytes:333706343 (318.2 MiB)
                    Interrupt:18 Base address:0xd800


(address details fudged only)

Re:

[cait56 (677299)]

FCOE really does rely on "new fangled technology". More than switched ethernet is required, it has to be an enhanced Ethernet that prevents virtually all congestion related drops.

Work on such features is indeed in progress in both IEEE 802.1 and the IETF. The comparison of FCOE vs. iSCSI in those environments will be a lot more even than the comparisons presented by FCOE champions currently. Those compare storage traffic that requires neither routing or security, and tests FCOE over forthcoming Ethernet

Re:I'm more interested in AoE

[Hal_Porter (817932)]

You should give it a snappier name like Serial ATA Networking, or SATAN. Lots of interesting logo possibilities in that, and it'll be funny watching 'technology evangelist' types stutter, sweat and mumble when they give PowerPoint presentations to born again potential customers.

Re:

[jd (1658)]

That acronym is already used by a security scanner. (Which had a patch which renamed it SANTA for evangelical network admins.)

Re:

[psydeshow (154300)]

FreeBSD is sometimes a tough sell to religious groups because of the devil mascot.

"You want to put... a demon? On our server?"
"Daemon, it's a daemon."
"..."

Re:

[jd (1658)]

But that only works correctly for Holistic Ethernet Link-Layer data centers providing Basic Realtime Infrastructure Management Support Technology Over Nextgen Ethernet.

Re:

[Intron (870560)]

How is ATA over ethernet offtopic in a discussion about a way of migrating SAN technology to ethernet?

ATA, SATA and SAS all have severe connectivity limits. They don't have a way of addressing a large number of devices, running long distances or supporting multiple initiators. While they might be fine for your home they are worthless for the SAN/LAN environment where fibre channel and FCoE are targeted.

Re:

[Creepy (93888)]

I see this as a benefit to smaller companies that need high speed storage, but maybe can't switch their entire storage network to fibre channel overnight due to cost. Many routers run Linux, so router manufacturers can probably add this functionality to existing Ethernet routers without hardware changes, making the cost of migration much smaller in the short term.

Re:

[Intron (870560)]

Is somebody running SAS more than 8 meters?