On Tue, 2 Dec 2003 10:10:34 -0500 (EST) Jerry McAllister <[EMAIL PROTECTED]> wrote:
> > > > Hope someone will have the pacince to read all this ... > > > > I have a 120G HDD, in the BIOS is set as LBA. I've RTFM as much as I > > could, but there still are some things I clearly don't understand. I > > want to be sure that I can move this disk to another machine with > > anouter BIOS and the system still boots up. > > > > I've used sysinstall to make partitions and the result is bellow: > > The basic and general answer to most of this is that nowdays with > modern disks, the Cylinder/Head/Sector values are essentially fiction. > They are based on values that can no longer be used with larger > disks and the system just generates values to make things happy. > The controllers are able to map the "absolute" sector number to > the correct place on the disk - which, bny the way, might even be > remapped due to sector errors and you don't even know it; it doesn't > tell you about those until there are more bad sectors than it has > spares for remapping. I know (end even with SMART I don't like it - You usally find out about it when nothing can be done). > Just go by the total number of sectors. Let fdisk do its thing. > It does it right. Do not try to set any Cylinder/Head/Sector > values. Ignore that part of things. For all practical purposes, > that part of things is obsolete. Even though some parts of the > system still fiddle with it, nothing really happens with it. About > the only thing it might want is for slices to begin and end on > cylinder boundaries and since you really can't control those, just use > the numbers it gives you as a divider to make sure your proposed slice > > size comes out even and then go with it. What I fail to see is the corespondence between sector and capacity in something like MB or KB. > So, choose the slice sizes you want by total number of blocks/sectors > and then use the -t switch to see what happens just to make sure the > sizes work out the way you want and then trust fdisk to do what is > right. > > > it# fdisk ad0 > > Try doing" > "fdisk -s ad0" > > To read the disk information. It gives you all the information that > is usually meaningful and is less confusing. I did: it# fdisk -I ad0 ******* Working on device /dev/ad0 ******* it# fdisk -s ad0 /dev/ad0: 232578 cyl 16 hd 63 sec Part Start Size Type Flags 1: 63 234438561 0xa5 0x80 So: 234438561+63 = 234438624 If I add the sizes in sectors from the previous I get sysinstall 234436545 fdisk-by-hand 234436482 The difference is exactly 63 and none match with this new one. Why ? > > Media sector size is 512 > > Warning: BIOS sector numbering starts with sector 1 > > Information from DOS bootblock is: > > The data for partition 1 is: > > sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD) > > start 63, size 497952 (243 Meg), flag 0 > > beg: cyl 0/ head 1/ sector 1; > > end: cyl 30/ head 254/ sector 63 > > The data for partition 2 is: > > sysid 6 (0x06),(Primary 'big' DOS (>= 32MB)) > > start 498015, size 41929650 (20473 Meg), flag 0 > > beg: cyl 31/ head 0/ sector 1; > > end: cyl 1023/ head 254/ sector 63 > > The data for partition 3 is: > > sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD) > > start 42427665, size 192008880 (93754 Meg), flag 0 > > beg: cyl 1023/ head 255/ sector 63; > > end: cyl 1023/ head 254/ sector 63 > > We haven't changed the partition table yet. This is your last > > chance. parameters extracted from in-core disklabel are: > > cylinders=232578 heads=16 sectors/track=63 (1008 blks/cyl) > > > > Figures below won't work with BIOS for partitions not in cyl 1 > > parameters to be used for BIOS calculations are: > > cylinders=232578 heads=16 sectors/track=63 (1008 blks/cyl) > > > > Information from DOS bootblock is: > > 1: sysid 0 (0000),(unused) > > start 0, size 497952 (243 Meg), flag 80 (active) > > beg: cyl 0/ head 0/ sector 1; > > end: cyl 493/ head 15/ sector 63 > > 2: sysid 6 (0x06),(Primary 'big' DOS (>= 32MB)) > > start 498015, size 41929650 (20473 Meg), flag 0 > > beg: cyl 31/ head 0/ sector 1; > > end: cyl 1023/ head 254/ sector 63 > > 3: sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD) > > start 42427665, size 192008880 (93754 Meg), flag 0 > > beg: cyl 106/ head 15/ sector 1; > > end: cyl 127/ head 14/ sector 63 > > 4: <UNUSED> > > Should we write new partition table? [n] y -- IOnut Unregistered ;) FreeBSD user _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"