On Wed, 2003-01-15 at 11:27, Robert P. J. Day wrote: > > ok, here's another question to which i don't know > the answer -- where does the first partition (/dev/hda1) > really start? > > i ask since, on my host, fdisk tells me that /dev/hda > has 255 heads, 63 sectors, 5836 cylinders (obviously bogus > values), but it further says that > > Units = cylinders of 16065 * 512 bytes > > or that cylinders represent 8M, which seems to match > nicely with the subsequent partition sizes. > > but since fdisk also shows that my /dev/hda1 partition > starts at cylinder 1, not 0, does that mean it skips an > entire "cylinder" from the beginning of the disk? > > if so, then you haven't really toasted /dev/hda1. > but i'm not sure if this is what these values are > telling me. > > anyone else have an opinion? >
try fdisk -lu /dev/hda According to the man page the u option will spit out start and end points of partitions in sectors. on two of my boxes I get the first partition starting on sector 63 with 512 byte sectors. assuming zero based numbering of sectors that is only the first 32256 bytes (63X512). I think that means the first prtition begins 32256 into the drive. beginning of hda1 would be wiped out in the case of the first meg being over written. I agree that the first order of business would be to get a valid partition table written by using Roberts suggestion on hexdump I see the beginning of the first partition at byte x0008000 so If Im am doin the math right, 16x16x16x8 or 32768 with a difference of 512 from the calculated size of the area before the beginning of the first partition 63 I am obviously not seeing this absolutly correctly but I think I am on the right track. here is what I found. Device Boot Start End Blocks Id System /dev/hda1 63 64259 32098+ 83 Linux /dev/hda2 * 64260 4160834 2048287+ c Win95 FAT32 (LBA) /dev/hda3 4160835 40066109 17952637+ 5 Extended /dev/hda5 4160898 10313729 3076416 83 Linux /dev/hda6 10313793 13398209 1542208+ 83 Linux /dev/hda7 13398273 13912289 257008+ 83 Linux /dev/hda8 13912353 14426369 257008+ 83 Linux /dev/hda9 14426433 14940449 257008+ 82 Linux swap /dev/hda10 14940513 15454529 257008+ 83 Linux /dev/hda11 15454593 40066109 12305758+ 83 Linux from the hexdump showing the beginning of the first partition 00001c0 001 \0 203 þ ? 003 ? \0 \0 \0 Å ú \0 \0 200 \0 00001d0 001 004 \f þ 177 002 004 û \0 \0 ? 202 > \0 \0 \0 00001e0 A 003 005 þ ÿ ÿ C } ? \0 û Þ # 002 \0 \0 00001f0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 U ª 0000200 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 * 0008000 M S - D O S 6 . 2 P C M N \0 0008010 \0 \0 \0 \0 D C C C 003 C : \ D O S \0 0008020 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 \0 * well now that I look at it the first partition according to fdisk is linux but if the stuff at byte x8000 is some sort of partition identifier it is showing MS-DOS 6.2 hmmm. This machine had windows on it at one time otherwise I don't know. I thought I was beginning to understand this. HTH Bret -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED]?subject=unsubscribe https://listman.redhat.com/mailman/listinfo/redhat-list
