Linux, Fibre Channel and SAN? 7
cybermage asks: "I'm in the process of researching a dense storage system to provide storage for a web farm. I've found some cool boxes that provide 584GB in 2Us but am a bit puzzled about getting Linux to talk to them. After looking at this past article from July, I'm wondering if any new advances in with Linux and Fibre Channel SAN solutions and whether anyone out there has some practical advice/limitations on sharing a large SAN amongst several Linux servers?"
DataDirect Networks - SAN Data Director (Score:2)
VA Linux has a NAS solution (Score:1)
Re:VA Linux has a NAS solution (Score:1)
oops
Re:DataDirect Networks - SAN Data Director (Score:2)
You have to decide your requirements first. (Score:1)
Cost and uptime will factor into the choices available to you.
How many machines do you want to connect to the storage? A fiber Channel Arbitrated Loop supports over 100 devices, but 80 may be a better limit. You can start with say, 10 servers, a SAN storage unit, a FCAL HUB (such as made by (Gadzoox).
If you want more, you're looking at a Fabric switch such as a Brocade which can get expensive quickly.
Talking to the SAN should not be a problem as far as the storage device is concerned - its the drivers for your fiber channel card that need to support linux. You can look at JNI, Emulex or Qlogic - some of these will have linux support.
To save cost, you can have a SAN raid that has disks attatched to the raid controller via LVD, with only the link between the HBA and controller being FC. Alternatively, you can get a 'full fiber' system. One sold by Dothill http://www.dothill.com can accomodate up to 80 or 160 73G drives depending on configuration, but for what you are taling about, they have a system called the 7120 that packs up to 10 73G drives, dual RAID controllers, N+1 fans and power supplies all into 4RU. And everything is hot swappable.
Check the vendors software for Linux support. Software may be for configuration, dual pathing etc. Some people make Java software, but I have seen problems with some of these under linux.
For a great SAN tutorial, have a look at http://www.dothill.com/tutorial/index.htm it explains all the terms and everything you need to het started.
Fiber Channel card -- usage reports available (Score:3)
At that web site they have a section where you can see the current status of all the Fiber Channel controllers and drivers for Linux, including other people's experience with different FiberChannel cards.
Namely, you can find it here: http://www.sistina.com/gfs/howtos/fibrechannel_ho
Hope that helps.
Emulex HBAs (Score:1)
At least Emulex [emulex.com] have Linux drivers for several of their PCI FC cards, which will also work on cards that use their chipsets.
Have a look at the docs [emulex.com] for installing the LP8000 [emulex.com] under Red Hat. (Source Code appears to be included.)
Everything after the card should be cross-platform anyway. I'm familiar with the Compaq StorageWorks stuff under NT, but a properly configured SAN looks like a bunch of SCSI drives to the server, which can do what it wants with them - no limitations on partition types etc. More SAN-specific functions are done through serial or telnet.
(I do not speak for any of the companies mentioned.)