On Tue, Feb 13, 2007 at 04:50:27PM +0100, frantisek holop wrote: > hmm, on Tue, Feb 13, 2007 at 08:18:50AM -0500, Kenneth R Westerback said that > > OpenBSD aligns to boundaries. It just makes up the boundaries, as do > > other OS's. It's unfortunate that all OS's don't make up the same > > boundaries but until you can convince all OS developers to use the > > same fake geometry you'll have to live with the current situation. > > > > OpenBSD makes absolutely no effort to get 'real' geometry > > information from USB attached disks. Too many such devices simply > > freak out and stop working when asked this difficult question. > > Others make up even more bizarre geometries than the one we use. > > > > So OpenBSD uses 64*32, divides the number of sectors (which all > > devices do provide) by this value to give a cylinder count, and > > truncates the fractional cylinder. So up to 64*31 = 1984 sectors > > will be 'wasted'. > > thanks for the src pointer, interesting. this explains the dmesg > clearly, but what about fdisk? fdisk is supposed to get the > geometry from the the bios (not much help for usb disks i guess) > and then the disklabel. is disklabel using the same fake magic? >
Yes. > > in the case of the 160G disk[1], there must be something wrong > as the dmesg total number of sectors is the same as the fdisk > total number of sectors, while it's pretty clear that not all > of the disk is usable and there is a 5103 sectors of waste... > > > i believe you when you say a lot of umass stuff is broken > and choking on basic calls. but wouldn't it make sense > to tell sd_get_parms() to go ahead and query an actual > geometry in case of "external hdd" usb devices? are the > usb disks just as broken as any random umass device in this > respect? > > > i don't have a netbsd install to test it, but their approach > seems te be not as discriminative towards umass devices[2]... > > > > btw this disk (wd passport) is strange in more respects. > first of all, partition magic got its geometry wrong also > a couple of times: > > 310,101 Cylinders, 16 Heads, 63 Sectors/Track but then > 19,457 Cylinders, 255 Heads, 63 Sectors/Track[2]. > > > second: > > 14:48:07 a /bsd: sd0(umass0:1:0): Check Condition (error 0x70) on opcode 0x2a > 14:48:07 a /bsd: SENSE KEY: Illegal Request > 14:48:07 a /bsd: ASC/ASCQ: Logical Block Address Out of Range > 14:50:21 a /bsd: sd0(umass0:1:0): Check Condition (error 0x70) on opcode 0x2a > 14:50:21 a /bsd: SENSE KEY: Illegal Request > 14:50:21 a /bsd: ASC/ASCQ: Logical Block Address Out of Range > 14:50:56 a /bsd: sd0(umass0:1:0): Check Condition (error 0x70) on opcode 0x2a > 14:50:56 a /bsd: SENSE KEY: Illegal Request > 14:50:56 a /bsd: ASC/ASCQ: Logical Block Address Out of Range > 14:53:53 a /bsd: sd0(umass0:1:0): Check Condition (error 0x70) on opcode 0x2a > 14:53:53 a /bsd: SENSE KEY: Illegal Request > 14:53:53 a /bsd: ASC/ASCQ: Logical Block Address Out of Range > > so this baby is certainly going back where it came from... > > > -f > > 1. http://marc.theaimsgroup.com/?l=openbsd-misc&m=117133082530013 > 2. http://opengrok.netbsd.org/source/xref/sys/dev/scsipi/sd.c#sd_get_parms > 3. http://marc.theaimsgroup.com/?l=openbsd-misc&m=116475065104125&w=4 > -- > the word of the day is legs. now spread the word!
