Selecting interconnects to test hardware

[distracted247]

Basic SAN question

Hardware for home SAN


I have recently acquired the following hardware but I am lacking some parts and the knowhow needed to get it up and running. I hope you can help!



I have the following:

Fujitsu Fibrecat SX80 x2
Server: 5504 CPU, 20GB RAM, Rack mounted
EMC Brocade Silk Worm 4100b Fibre Switch
Cisco Catalyst 2950-24 slot 10/100 + 2 GBic x2
Plus all the drives I need to populate 1 Fibrecat and the server.

What I would like to know is, can I install any brand of Fibre Channel HBA in the server or does it need to be one recommended by, or from the server manufacturer?

The same question applies to cables - are all fibre cables created equal or should I look for anything in particular?

Thank you to anyone who takes the time to read this!

 

[distracted247]

Thank you to the mod who moved this - I wasn't sure if it really was considered DIY since I was using preconfigured boxes.

 

[kanewolf]

Have you established ethernet connectivity to the Brocade? It has a lot of capabilities to trouble shoot fibre channel.

The firmware on a re-branded HBA might be "tweaked" by the reseller. Generally it should work.

As for fiber cables, you probably aren't pushing the length limits, so even 62.5 will probably work. But 50 micron would be preferred. Even for 4Gb (you used a capital B implying Bytes when it is really bits) fibre channel, teal (10Gb) fiber is not required.

 

[distracted247]

Thank you for the reply. I haven't made an ethernet connection to the switch yet - I'll search for a manual and see if I can work through the tools.

Thank you for the tip and the advice

 

[GregN]

HBA's should be compatible. If using two speeds I'd recommend putting the slower one on the initiator.

You may want to try, initially a point to point connection and see if the initiator sees the target. Then put the switch into the mix. Kanewolf is right about this, net connecting over the management channel should let you see any issues.

Only issue around the cable is the connectors, is the switch LC and the HBA LC. Some switches have SC connectors. The wavelength is ( as stated ) a function of distance.

 

[distracted247]

The FibreCat Raid controller has the fibre port built in so that will be 4Gb regardless of the HBA i eventually to put in the Server.
I am aiming for a 4Gb HBA though, since the SAN article suggests it is the sweet spot price/performance wise on eBay atm.

I'll check the connectors on the switch and the Storage unit and see what type they are to be sure I get the right cable.

Am I understanding you when I say that since the Server and the first storage box will be in the same rack with only 1U between them, I don't need to worry about wavelength?

Thanks again for the feedback!

 

[GregN]

Yes, Wavelength shouldn't be an issue at that distance, dealers choice.

I did some digging on your switch and the cable type should be LC, but is dependent on the type of pluggable transceiver you have in the switch.

What OS are you going to be running on the Target?

Two Fibrecats, that why you are running a switch instead of Peer to Peer?

 

[distracted247]

Thank you, that's also the info I found for the cable termination. I'm just searching for a suitable cable at the right price at the moment.

Is there a reason I shouldn't be running a switch? I haven't got any experience with this so I'm literally just working with what I have available. I can leave the switch out of the mix if it will cause a problem.

Thanks again.

 

[distracted247]

The OS will be either something freely available or some form of windows server. I would like to experiment with virtual machines so I was hoping the hardware would work with most forms of OS. If it helps I expect I will start with server2008 and run VMs from within since I know little about the alternatives at the moment.

I know the fibreCats are certified for quite a few OSs.

 

[GregN]

Interesting.

No, I wasn't suggesting you eliminate the switch, just wondering why you decided to go with the switch. The reasoning behind your equipment choices.

Is this a trunkload of equipment that you ended up with?

 

[distracted247]

I had no intention of getting a switch but while I was trying to source a suitable Fibre Card I was offered a stonking deal for the switch so on impulse (and with a vague recollection of the SAN article in the back of my mind) I bought it.

In my mind I remembered that it was decided that a direct link would be used due to price and somewhere along the line I must have made the assumption that if price were no object a switch or looped type would be the better choice since performance wasn't mentioned as a reason for choosing point to point.
TBH I think my subconscious was just won over by the value the switch represented rather than any real need for it and decided to present my memory to me as it saw fit... that seems to happen a lot

If i don't use the switch though i can sell it on for what i paid and there's no harm done. Would i be right if i said that not having a switch will limit the amount of fibre connections to my SAN?

 

[GregN]

I had no intention of getting a switch but while I was trying to source a suitable Fibre Card I was offered a stonking deal for the switch so on impulse (and with a vague recollection of the SAN article in the back of my mind) I bought it.

In my mind I remembered that it was decided that a direct link would be used due to price and somewhere along the line I must have made the assumption that if price were no object a switch or looped type would be the better choice since performance wasn't mentioned as a reason for choosing point to point.
TBH I think my subconscious was just won over by the value the switch represented rather than any real need for it and decided to present my memory to me as it saw fit... that seems to happen a lot

If i don't use the switch though i can sell it on for what i paid and there's no harm done. Would i be right if i said that not having a switch will limit the amount of fibre connections to my SAN?

Switch is added complexity, complexity that you might use or might just be more hassles. Sharing the same RAID unit across multiple machines is not easy, so generally folks create separate units ( carving ) and connect them to separate nodes which does need a switch ( One SAN, multiple DASes ).

Like you saw in the SAN articles, I recommend starting simple and building on that.

As far as I know Openfiler only supports QLogic currently, and other distros have challenges using FC HBAs (you might have to put together a custom kernel)

NexentaStor is probably your best bet.

 

[distracted247]

Thanks for the info, extra (!) complexity isn't something I need so I will wait a while on adding the switch to the mix.

Thanks!

 

[distracted247]

So I got myself a couple of 2 port QLogic 10Gb CNA PCIe cards and while I'm waiting for them to arrive I'm trying to work out exactly what is needed to connect to my Fibrecat.

I know that I can't use a regular SFP transceiver and that I have to use SFP+ but I see so many different types it's hard to know where to start and on top of that there are also cables with the transceivers built in by the looks of it. Add to that the wavelengths and the acronyms... don't get me wrong I am doing my own research, I'm just saying it isn't straight forward!

Anyway, I'm going to continue to search for a few white papers on the subject and do more of my own research but I would appreciate it if I could get some advice here based on my specific scenario. Any constructive feedback you can give would be really great!

Oh and I don't have the switch any more so I 'hope' things will stay fairly straight forward now that I am aiming for point to point connections.

 

[kanewolf]

10 Gig-E for "normal" distances of under 100 meters would be an SR SFP+. Fifty micron cable can be used for very short distances (20 meters or less) otherwise, 10 Gig-E (normally teal colored) fiber should be used. 10 Gig E fiber is not typically very much more expensive than regular 50 micron cable.

 

[distracted247]

Thanks to everyone for their help with this.

I wanted to quickly post to say thank you before I took the time to do a proper write-up of how I eventually gathered all the hardware together.
Hopefully that will come when I have the time to think about it properly and edit it.

For now though, thank you all for your assistance!