Alexander Veit wrote: >Richard Fish wrote: > > > >>Alexander Veit wrote: >> >> >> >>>geometry = 4867/255/63, sectors = 78198750, start = 0 >>>geometry = 65535/16/63, sectors = 40037760000, start = 0 >>> >>> >>> >>Well, the obvious thing for me is the difference in the drive >>geometries >>between the two systems...the 2.6 kernel is seeing the entire drive >>while the 2.4 kernel is only seeing ~39G worth. I remember seeing a >>message somewhere that LBA48 addressing was pretty slow on some >>systems. I'm googling now, if I find anything I'll post a followup. >> >> > >Another difference is the kernel version Gentoo 2.6.11, Knoppix 2.4.23. > >I've just tried Knoppix 3.8.1 which comes with Linux kernel 2.6.11, and > > > geometry = 65535/16/63, sectors = 78198750, start = 0 > >
Bizarre....this is with the new Knoppix?? I would have expected it to see the whole disk. >the buffered read performance is 17,44 MB/sec as with Gentoo. What does this >mean? > > The geometry line above not-withstanding, I think the 2.4 kernel on your old Knoppix disk doesn't support lba48 (disks >137GB) addressing, which is changing the equation considerably on accessing the disk. Try going into the BIOS and change the disk access mode from "large" to "lba", then repeat your timings and geometry ID with new Knoppix/Gentoo. Also, it might be interesting to see the dmesg output for the IDE controller. This is really just an experiment...even if I am right about the problem I don't have a solution. -Richard -- gentoo-user@gentoo.org mailing list
