> > > > > RAID-6 layout: http://www.acnc.com/04_01_06.html > > > > > > If it is supposed to survive two arbitrary disk failures something is > > > wrong with that figure. They store 12 logical sectors in 20 physical > > > sectors across 4 drives. With two lost disks there are 10 physical > > > sectors left from which we want to reconstruct 12 logical sectors. > > > That is impossible. > > > > Might be the diagram is wrong. > Could be the case, so until I find another description I will > still not know how RAID-6 works. Below is a (patented?) version that works. This is from the linux-raid list > A1 A2 (P1) (PA) > (P2) (PB) B2 B1 > C4 C3 (PC) (P3) > (PD) (P4) D3 D4 > > Disclaimer: I took that from Patent 6,353,895. If you look it up you'll see > a lot of different schemes and discussion of XOR-based RAID 6, in language > disguised as English. You'll also see that I'm listed as the inventor. > That's four companies back for me, but my current employer unknowingly > has some rights to it, so I hope it will see the light of day sometime. > > Dale Stephenson > steph@snapserver.com -- Roy Sigurd Karlsbakk, Datavaktmester Computers are like air conditioners. They stop working when you open Windows. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
