Manual partitioning for newbies

[Dimitry Andric]

On 2010-01-21 10:30, Ivan Borodin wrote:
> Excuse me, haven't found a mailing list for newbies...

That would be freebsd-questions@, AFAIK.


> [root@ ~]# fdisk -s /dev/ad5
> /dev/ad5: 19383 cyl 16 hd 63 sec
> Part        Start        Size Type Flags
>     1:          63    19538001 0xa5 0x80
>
> [root@ ~]# atacontrol cap ad5 | grep lba
> lba supported         19538975 sectors
> lba48 not supported
>
> Seems like sysinstall threw away 974 sectors while partitioning..

This is because partitions are aligned to cylinders by default.  In your
case, the disk says it has 19383 cylinders, 16 heads and 63 sectors per
track, so that is 19538064 sectors total.

In some cases, disks advertise more LBA sectors than they would seem to
have if you calculate cyl * hd * sec.  This is because the 'geometry' is
entirely fake, and sometimes doesn't fit the real number of available
sectors.

So in your case, there are 911 sectors slack space at the end.  Not the
end of the world. :)

Btw, if 'dangerously dedicated' partitions are still supported in your
version of sysinstall, you might be able to use the whole LBA capacity
for your slices.