FreeBSD slices and the Boot Manager

Warren Block wblock at
Sun Jul 28 16:50:29 UTC 2013

On Sun, 28 Jul 2013, Polytropon wrote:

> On Sun, 28 Jul 2013 08:18:39 -0600 (MDT), Warren Block wrote:
>> On Sun, 28 Jul 2013, Polytropon wrote:
>>> On Sat, 27 Jul 2013 19:39:30 +0200 (CEST), Conny Andersson wrote:
>>>> A very important question is if sysinstall's option "Install the FreeBSD
>>>> Boot Manager" detects that I have a FreeBSD 8.3 and detect it as slice 2 on
>>>> disk 1?
>>> I'm not sure I'm following you correctly. The sysinstall program
>>> is considered obsolete, the new system installer is bsdinstall.
>> AFAIK, sysinstall is still used in FreeBSD 8.X, and bsdinstall does not
>> have a boot manager option anyway.
> Sometimes I'm confusing them, because I usually don't use the
> installer and usually use fdisk (if needed), bsdlabel and
> newfs. :-)

gpart does a lot more than both fdisk and bsdlabel, and is easier to 
use. :)

>>>> So it becomes a boot option when I am rebooting? (Maybe the slice
>>>> may come up as ad6s2, because AHCI in FreeBSD 8.4 isn't enabled at the time
>>>> of the install.)
>> Sorry, I don't understand this at all.  AHCI should not be involved with
>> identifying slices.
> Maybe the required device driver is not part of the 8.x
> GENERIC kernel? So for example a drive could come up either
> as /dev/ada0 or as /dev/ad6, depending on how the recognition
> order and PATA / SATA thing is handled by the system and
> its BIOS.

Really, it should always be ada, unless someone has built a custom 
kernel that intentionally uses the old form.  That's usually a mistake.
(AHCI is a separate, unrelated thing.)

> Labels will work independently from wheather the device will be 
> recognized as ATA disk (for example /dev/ad6s1a being the root disk) 
> or SATA disk (where /dev/ada6s1 would be the root disk).

Yes.  Labels don't care about the hardware connection.  So they'll 
continue to work when you take a drive out of a machine and put it in a 
USB enclosure, for example.

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