I think Sergey is onto something. Looks like there is a host protected area on that disk and it roughly matches the size of the offset we're seeing after the metadata. So what's the deal with HPA and why does the kernel after 2.6.10 (I think I read) simply disable it? Anyway it's looking like that is the problem. Here's the relevant part of dmesg: hde: max request size: 128KiB hde: 78156288 sectors (40016 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100) hde: cache flushes not supported hde: unknown partition table hdg: max request size: 128KiB hdg: Host Protected Area detected. current capacity is 78125000 sectors (40000 MB) native capacity is 78165360 sectors (40020 MB) hdg: Host Protected Area disabled. hdg: 78165360 sectors (40020 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100) hdg: cache flushes not supported hdg: unknown partition table Possible solutions: The kernel doesn't disable the HPA but instead ignores it. (In theory then bringing our metadata back to totalSectors - 63) The kernel continues to disable it and dmraid figures out about the HPA then factors that in as an offset when looking for metadata Anyone know more about the decision to disable HPA in the kernel? What do you think would be the proper fix? Greg 2005/8/26, Sergey Vlasov <vsu@xxxxxxxxxxx>: > On Fri, 26 Aug 2005 10:15:41 -0600 Greg Felix wrote: > > > So this is proof to me that the BIOS is reading Disk 2 as 21MB (or > > 41000 or so sectors) less than the kernel is. > > > > So where's the problem? The BIOS? The Kernel? The IDE disk? And why > > does the RAID work in Windows? > > Can you provide the full dmesg output? > > Maybe Disk 2 has host protected area enabled; recent Linux kernels > disable HPA unconditionally, and this could explain the difference in > capacity. > > > _______________________________________________ Ataraid-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/ataraid-list
