Date: Wed, 10 May 2006 09:12:31 -0700 From: "Atom Powers" <atom.powers@gmail.com> To: "cknipe@savage.za.org" <cknipe@savage.za.org> Cc: freebsd-questions@freebsd.org Subject: Re: OT: Torn between SCSI and SATA for RAID Message-ID: <df9ac37c0605100912s46bffe8an7c1212c4ca0330e5@mail.gmail.com> In-Reply-To: <1147255200.4461b9a0a5e71@196.22.132.16> References: <1147255200.4461b9a0a5e71@196.22.132.16>
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> > Another thing that I read that I'm not completely sure about. Some of th= e > Adaptec SCSI Cards advertises a max of 30 devices - some even more. Excu= se the > ignorance, but does the SCSI Bus not allow for a max of 8 devices? Do th= ese > cards then feature multiple buses to connect the cables to? If so, SATA = will > obviously not be able to provide something like this. I am not that familiar with SCSI protocols, but I imagine the Ultra-Wide SCSI bus can probably address 32 devices ( 31 drives + the controller ). > Now comes my question... Uhm.. Can SATA RAID Controllers be 'linked'. Sa= y, I > but 4 x 8-Port Adaptec SATA RAID Controllers... 2 x 8 Port Cards =3D 16 P= orts for > 1 RAID 5 Array (@ 750GB Drives, 12TB Max). The other 2 cards, to mirror.= I > know that I can use one Controller to mirror another, but can I extend a = array > across multiple controllers... And then naturally, just HOW much slower d= oes > the array function? I imagine you would probably have to use software raid at that point. And even if you would use two controllers togeather (SLI for RAID?) you would be limited by the PCI bus. > > I've seen some comments and posts (esp. on slashdot) made where people go= about > running massive arrays successfully on SATA. Given the limits on the Por= ts at > the controller, just how is this achieved? Probably with softawre RAID. With software RAID you can even mix drive types, like SATA, PATA, SCSI, USB, etc. But it's much slower. > Sorry that this is so OT, but I hope I'd get some good answers. This is > definately not something that's been discussed allot before considering t= he > amount of info I got after spending a number of days on google... > > -- > Chris. > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" > -- -- Perfection is just a word I use occasionally with mustard. --Atom Powers--
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