On Mon, Jun 25, 2007 at 10:18:14AM -0700, Gaston, Jason D wrote: > > > >Eg, PC Magazine: > >"RAID 10, RAID 100 - Speed and Fault Tolerance > >RAID 10 is RAID 1 + 0. The drives are striped for performance > >(RAID 0), and all striped drives are duplicated (RAID 1) for > >fault tolerance." > > > >Yes, I konw, there's different (aargh!) definitions out there. > > > >Like I said: the top -> bottom of the stack definition is preferable > >to me (you reach the mirror first and the stripe second while walking > >the stack from the top to the bottom). > > > >We just got to hold on to one definition in dmraid, > > > >Heinz > > > > Ok, so the dmraid definition is not going to change. I'ld much rather avoid it :-) > > Do you see an advantage in putting the RAID1 vs. RAID0 on the bottom for > being able to perform rebuilds easier? I need to decide which way to do > with isw. Talking about either a mirror on top of stripes or a stripe on top of mirrors, it is merely a question of IO minimization on rebuilds. Ie. when a stripe below a mirror breaks, you've got to resilver the whole stripe set, hence writing 2 or more drives rather than just one disk in a mirror set beneath a stripe. With respect to ease of rebuilds at the programming level, there's no difference in changing the mapping of a top level mirror to do a full resync vs. a bottom level mirror. Getting back to your decision: you could support both ;-) Cheers, Heinz > > Thanks, > > Jason _______________________________________________ Ataraid-list mailing list Ataraid-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ataraid-list
