On Tue, Jan 28, 2014 at 06:56:32PM -0600, Stan Hoeppner wrote: > On 1/28/2014 10:50 AM, Marc MERLIN wrote: > > On Tue, Jan 28, 2014 at 01:46:28AM -0600, Stan Hoeppner wrote: > >>> Today, I don't use PMPs anymore, except for some enclosures where it's easy > >>> to just have one cable and where what you describe would need 5 sata cables > >>> to the enclosure, would it not? > >> > >> No. For external JBOD storage you go with an SAS expander unit instead > >> of a PMP. You have a single SFF 8088 cable to the host which carries 4 > >> SAS/SATA channels, up to 2.4 GB/s with 6G interfaces. > > > > Yeah, I know about those, but I have 5 drives in my enclosures, so that's > > one short :) > > I think you misunderstood. I was referring to a JBOD chassis with SAS > expander, up to 32 drives, typically 12-24 drives with two host or two > daisy chain ports. Maybe an example would help here. > > http://www.newegg.com/Product/Product.aspx?Item=N82E16816133047 Ah, yes, that. So indeed in the price category of a PMP chassis with 5 drives ($150-ish), I haven't found anything that isn't PMP or 5 sata cables. > Yeah, something definitely not right. Your RAID throughput is less than > a single 7.2K SATA drive. It's probably just something funky with that > JBOD chassis. That's also possible. If/when I have time, I'll unplug things and plug the drives directly to the card as well as try another MB. Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/ -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
