4

I have two Sun servers running Solaris 10. Both have Emulex fiber channel cards. I'd like to connect the two in a "crossover" fashion like you would copper ethernet & IPv4. Point being I have a ZFS array attached to one that I'd like to share to the other via NFS over fiber channel. These are for testing/development, so no budget for a switched fabric.

How would I go about setting this up? I'd appreciate any experiences shared, doesn't have to be Solaris based.

2
  • You'll need to get the Fibre Channel link layer up and running, and then configure IP on it. I'm not sure that the latter is even possible on solaris; RFC 4338 is a PROPOSED standard for this, not sure it was ever ratified. Alternately, you could use solaris's native fibre channel target provider, and export ZFS volumes as block devices. That is not the same as doing NFS though; both hosts will not get access to filesystem-layer stuff, I don't believe.
    – Dan Pritts
    Jan 2, 2013 at 21:39
  • My main concern is whether or not it'd actually work or if it'd damage the HBA's (kinda joking). For example, old crossover between copper NIC's required a special CAT5 cable. Any copper NIC in the last several years can do crossover automatically. Never heard of doing this via fiber, which is why I'm asking if it'd actually work.
    – churnd
    Jan 6, 2013 at 22:16

1 Answer 1

2

Based on your comments your question is about how to go and connect the devices physically, and not about the config. In that case you just need to create a rollover cable from the normal fiber cable you probably have already. Most fiber cables have separate connectors (LC/SC) only held together by a small plastic clip or a small shell that you can take apart or bend enough to take the connectors out of it (this is perfectly safe, it's how they meant to work), reverse their order and reassemble the duplex connector. Now you have as crossover cable, tx goes to rx on the other side and vice versa. This is common practice with patch panels.

There is at least 2 kinds of different adapter types. FiberChannel and Ethernet. The main difference is encoding and protocols.

FC uses an 8/10 encoding, meaning that every 8 bits have a 2 bit parity attached, meaning that in case of a 10Gb HBA you get a 8GB FC link. It also uses FCP as the transport protocol (similar to TCP), it transports SCSI commands over Fibre Channel networks. And actually a whole different stack.

On the other hand, Ethernet NICs don't have this encoding, so a 10Gb NIC will bring up a 10Gbps link. You can't mix and match these adapters as they will not bring up a link.

FC over Ethernet does exist, it would use a mixed network which requires a type of hybrid adapter (called converged network adapters), which has both a NIC and a HBA, where the FC frames are encapsulated in Ethernet frames, on the end devices split and handled separately.

2
  • Cool thanks! I'll try that. Another question is, are all fiber cards made alike, or are some made for storage & others for network?
    – churnd
    Jan 28, 2013 at 20:21
  • Added the explanation to the article as it doesn't fit here.
    – psarossy
    Jan 29, 2013 at 9:35

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .