Les Mikesell wrote: > The only relevant part of the backplane is that > it uses SCA connectors which you need for hot swapping > because they make the power and data connections happen > in the right order. The controller doesn't know if > there is a backplane or just a cable. Chris Mauritz wrote: > That is my understanding as well, though I'm not a bona fide certified > electrical engineer (don't even play one on the net). 8-) Ummm, no, there's far more to a SCSI-2 backplane than just handling the transient. That is then feed back to the SCSI-2 host adapter. And depending on what the SCSI-2 driver can give the kernel, there's a lot more that _can_ be reported. And, my latter comment of ... "I'd have to fully research _what_ is exactly required -- at the SCSI card (probably not much), at the SCSI backplane (probably not much) and at the SCSI driver (there's the majority of the beef ;-)." SCSI-2 is a very rich command set, with a lot of control. I'm sure the backplane and host adapter offer a wealth of information, something that can be used. Again, I have to research what is different. But _regardless_, you're _not_ going to get that out of a 3Ware, an Areca, etc... They have that capability _on_card_ in their firmware, executed by their ASIC/microcontrollers for their arrays. But they aren't feeding back such a rich set of capabilities to the OS. And that's before we even look at standard ATA controllers. There is a rich set of logic being developed for ATA, and "libata" attempts to support it. But nothing is well developed, much less well supported by various controllers, etc... So please quit nit-picking my comments, which you guys _always_ do. I have given far more dissection than _anyone_ here has even _bothered_ to address. I have given repeated, _sound_advise_ on what you can and can't use 3Ware for. There are far more many people going, "oh yeah, you can use 3Ware and get hot-swap with software RAID" on a whim over on the MD lists. I at least know what I have used. I'm honestly considering leaving this group because select people continue to want to over-simplify my comments just for the sake of disagreeing with them, and not seeing the larger issue of _all_ the factors involved. It's really not worth it if some of you guys don't want to work with me. And damn it if it isn't the same characters over and over and over again. Especially the ones that want me to provide documentation, yet they haven't offered any insight or documentation themselves. -- Bryan J. Smith mailto:b.j.smith at ieee.org http://thebs413.blogspot.com ------------------------------------------ Some things (or athletes) money can't buy. For everything else there's "ManningCard."