Re: gpart, bsdlabel and fdisk

On Oct 21, 2009, at 5:48 PM, Aristedes Maniatis wrote:

> On 22/10/09 4:54 AM, Marcel Moolenaar wrote:
>
>>> * is this the future for FreeBSD and we should use gpart from here
>>> on? Are the old tools deprecated?
>>
>> Yes.
>
> But the 8.0 sysinstall still uses fdisk and bsdlabel?

No, sysinstall has embedded code for partitioning.
It doesn't use fdisk, bsdlabel nor gpart.

>
>>> * is the result of using gpart completely different to the
>>> bsdlabel/fdisk we've known? Are the partitions on disk quite  
>>> different?
>>
>> The on-disk layout is dictated and cannot be different. As such,
>> they are the same.
>
> But some things look different. For example, old style labels were  
> always of the style ad4s1b.

ad4s1b means that ad4 has a MBR and in partition 4 of the MBR
is a BSD disklabel that has a 'b' partition. This is exactly
the same you get with gpart.

> But now the labels appear to be more flexible. Should we be using  
> old style labels for compatibility with old tools, or does  
> everything work with the new labelling options?

There's not really an old style or a new style. gpart (with
GEOM_PART in the kernel) is just a different way of creating
on-disk partitions. gpart does add some flexibility in some
cases (more than 8 partitions in the BSD disklabel), but it's
still a BSD disklabel.

>
>>> * is there some source of good documentation out there other than
>>> the man page for gpart?
>>
>> man gpart.
>
> Hmmm...  I was hoping for something more useful than that response.  
> Where is it documented that I have to do "echo 'a 1' | fdisk -f - / 
> dev/ad4" to make a disk bootable?

man fdisk :-)

Or with gpart:

# gpart set -a active -i 1 ad4


> Is there a work-in-progress handbook page somewhere that describes  
> the overall process of setting up disks with the new tools?

It typically takes a while for that to catch up with
events. I don't think there's a WIP just yet...

-- 
Marcel Moolenaar
xcllnt_at_mac.com