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Firewire and Linux?
aozilla asks: "I was just at Pricewatch, and I noticed that 80 gig firewire drives are available for only $200. My good old IBM Deskstar just crashed, so I'm in the market for a new hard drive, and I'd love to go with Firewire. External, hot-swappable and the ability to have more than 2 devices without significant slowdown are the main features I'd like on top of what I get from my IDE drives. I'd like to hear from those who have experience running firewire on Linux. How good is the driver support? Is hot-swappability really supported (just umount and unplug, plug and mount)? Are there any recommendations for PCI Firewire cards for Linux? How many drives can reasonably fit before power becomes an issue (I assume the less expensive drives obtain power from the port)? My main goals are capacity, cost, and convenience. Speed is not too much of an issue, and I'm more a fan of automated and explicit backups rather than RAID."
When you dig down into the SBP-2 layer of IEEE-1394 you will find that it is SCSI. SCSI commands and responses are used for the mass storage device on IEEE-1394. The only thing that is different is the physical and low level signal transmission. So, at the software level (once you get above the lowest level packet sender/receiver) there is no difference from scsi.
:-) A 12% cost savings will win in the end.
At the physical level you get to trade a 50 or 68 pin connector and cable for a 6 or 4 pin connector and cable. The controller chips probably cost about the same in volume, maybe a couple of bucks different. A good SCSI cable (and don't mess with bad ones) is $50. A good firewire cable is $7.
There is your reason. A $300 disk is $350 with
SCSI and $308 with Firewire. (I added a dollar for the $0.50 license fee on the ports at each end of the cable.
Non-tangibles such as easy configuration, the ability to pile a dump truck load of disks on a single interface, and not becoming ensnared in a wriggling mass of cables are just nice bonuses.
(I have used SCSI for ages, but now prefer IEEE-1394 for my archival storage machines. I still use SCSI for my high reliability and high performance machines, but that is more a Linux driver issue than anything intrinsically IEEE-1394.)
First, Firewire == Apple-branded 1394. IEEE 1394 is an IEEE spec, it has nothing to do with IBM.
Second, 1394 specifies both powered and unpowered connectors/cables. Powered is far more common. You'll see the unpowered connectors on cameras and Vaios. They're small and break off in the port.
Most devices use the powered connectors, even if they don't draw any juice. A wall-wart is always safer, since you may be sharing the power with other devices: good for recharging (iPod); bad for a reliable hard drive (but very convenient with a laptop..)