On 2/27/11 4:07 PM, "James C. McPherson" <j...@opensolaris.org> wrote:
>I misread your initial email, sorry. No worries-- I probably could have written it more clearly. >So your disks are connected to separate PHYs on the HBA, by virtue >of their cabling. You can see this for yourself by looking at the >iport@xx element in the physical paths: > >1. c13t5000CCA222DF92A0d0 >/pci@0,0/pci8086,340a@3/pci1000,72@0/iport@10/disk@w5000cca222df92a0,0 > >2. c14t5000CCA222DF8FBEd0 >/pci@0,0/pci8086,340e@7/pci1000,3020@0/iport@1/disk@w5000cca222df8fbe,0 > >The "xx" part is a bitmask, starting from 0, which gives you an >indication of which PHY the device is attached to. > >Your disk #1 above is connected to iport@10, which is PHY #4 when >you have x1 ports: > > >PHY iport@ >0 1 >1 2 >2 4 >3 8 >4 10 >5 20 >6 40 >7 80 OK, bear with me for a moment because I'm feeling extra dense this evening. The PHY tells me which port on the HBA I'm connected to. What tells me which HBA? That's the information I care most about, and if that information is contained up there I'll do a happy dance and head on in to the office to start building zpools. >With the information above about the PHY/iport relationship, I >hope you can now see better what your physical layout is. Also, >please remember that using MPxIO means you have a single virtual >controller, and the driver stack handles the translation to physical >for you so you don't have to worry about that aspect. Of course, >if you want to worry about it, feel free. Well, I want to make sure that a single controller failure can't cause any of my RAIDz2 vdevs to fault. I know I can do that manually by building the vdevs in such a way that no more than two drives are on a single controller. If the virtual controller is smart enough to do that automagically-- when I'm using SATA disks and a backplane that doesn't support multipathing-- then I have no complaints and I owe you a beer or three the next time you're in the Dallas area. But that seems unlikely to me, and so I think I have to worry about it. I'd love to be wrong, though! >Personally, having worked on the mpt_sas(7d) project, I'm disappointed >that you believe the card and its driver are "a failed bit". I'd like to revise and extend my remarks and replace that with "a suboptimal choice for this project." In fact, if I can't make this work my backup plan is to take some of my storage towers that have only one HBA, put the 9211s in them and grab the LSISAS3081 cards out of those towers for this beast. So those cards will still get productive use -- not a failed bit, at worst just not serving the purpose I had in mind. -- Dave Pooser, ACSA Manager of Information Services Alford Media http://www.alfordmedia.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
