Can't mount ad0s2 - sourced

[Malcolm Kay]

On Mon, 16 Jun 2003 10:58, Brian Astill wrote:
> On Mon, 19 May 2003 02:52 pm, Andy Farkas wrote:
> > > > Sure there is [a solution]. Show us what fdisk and disklabel say.
>
> referring to my being unable to access ad0s2 from FBSD.
> The drive is partitioned DOS-DOS-FBSD.
>
> If I set up the partitions Primary1-Primary2-Primary3, WinNT "hides"
> Primary2, and I have to "unhide" using Partition Magic every time I
> boot into that hateful OS.  However, I CAN acess Primary2 from FBSD.
> If I set up the partitions Primary1-Logical1-Primary2, WinNT is happy,
> but Logical1 cannot be mounted by FBSD.
>

Never had occassion to use this but:-

It's my understanding that so called logical partitions/slices are available 
to FreeBSD as slice 5, 6 ...
Thus you should be able to mount the elusive partition as ad0s5.
Of course you'll probably need to first make the device:-
  #cd /dev
  #./MAKEDEV ad0s5

> herewith details of the latter case:
> As you can see, fdisk can see the extended partition, but not the
> logical partition inside it. (tho' windoze is happy)
>
> #fdisk /dev/ad0
> ******* Working on device /dev/ad0 *******
> parameters extracted from in-core disklabel are:
> cylinders=1027 heads=255 sectors/track=63 (16065 blks/cyl)
>
> Figures below won't work with BIOS for partitions not in cyl 1
> parameters to be used for BIOS calculations are:
> cylinders=1027 heads=255 sectors/track=63 (16065 blks/cyl)
>
> 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 6,(Primary 'big' DOS (> 32MB))
>     start 63, size 2056257 (1004 Meg), flag 80 (active)
>         beg: cyl 0/ head 1/ sector 1;
>         end: cyl 127/ head 254/ sector 63
> The data for partition 2 is:
> sysid 5,(Extended DOS)
>     start 2056320, size 2088450 (1019 Meg), flag 0
>         beg: cyl 128/ head 0/ sector 1;
>         end: cyl 257/ head 254/ sector 63
> The data for partition 3 is:
> sysid 165,(FreeBSD/NetBSD/386BSD)
>     start 4144770, size 12353985 (6032 Meg), flag 0
>         beg: cyl 258/ head 0/ sector 1;
>         end: cyl 1023/ head 254/ sector 63
> The data for partition 4 is:
> <UNUSED>
>

Since logical slices are rather like primary slices
but referenced from a primary slice or another logical slice,
rather than the MBR, they can usually be "viewed" by 
pointing fdisk at a slice instead of the entire disk:
  #fdisk /dev/ad0s2

Malcolm