9.0 beta2 & the new bsdinstaller

[Kevin Oberman]

On Sun, Sep 18, 2011 at 5:52 PM, Fbsd8 <fbsd8 at a1poweruser.com> wrote:
> Kevin Oberman wrote:
>>
>> On Sun, Sep 18, 2011 at 2:55 AM,  <"Thomas Mueller
>> <mueller6727"@bellsouth.net> wrote:
>>>
>>> Some more ideas on the new bsdinstaller cross my mind.
>>>
>>> Since the way the bsdinstaller would make partitions is unpredictable, at
>>> least to the uninitiated, and in all likelihood at variance with how much
>>> space the user wants to allocate, it might be better to offer a roadmap to
>>> help guide the user to allocating space for FreeBSD using gpart or Rod
>>> Smith's gdisk.
>>>
>>> Also, I can't see the function of the 64 KB boot partition with no file
>>> system, which does not boot for me, though I can boot the main partition
>>> using grub2 from the System Rescue CD (http://sysresccd.org/).
>>
>> The 64KB freebsd-boot partition is to contain the GPT boot code which
>> is used by UEFI BIOS in
>> place of the old MBR used by legacy BIOS. You need to use gpart(8) to
>> write the GPT boot code to that partition, but I don't know if
>> bsdinstall does so. It might just write the PMBR that is used for
>> booting with legacy BIOS. I'll admit that I have not checked. (See the
>> gpart(8) man page for details on writing the pmbr and gptboot.)  I
>> assume bsdinstall writes both so that AMD64 machines with EFI and
>> 32-bit systems will both work. This is very different from the old
>> traditional slice/partition system.
>
> The above info is another example of the type of information that should be
> added to a "help" option on the dialog screen for the bsdinstall disk
> configuration function.
>
> I also think that the bsdinstaller should offer the user an option to select
> between using the old MBR configuration used by legacy BIOS that sysinstall
> uses and the new gpart configuration which bsdinstall offers now.

I can only see two advantages of the old MBR scheme over GPT.
1. Booteasy is not available, so you need to use gpart to designate
booting from a
different partition
2. Some other OSes don't support it. 32-bit Windows, Solaris, 64-bit Windows on
systems lacking EFI

While GPT has major advantages over the old MBR system, I think these two
justify maintaining the ability to install FreeBSD with MBR.

I also should be clear in that sysinstall does work fine on a disk
that is already
configured with MBR partitioning. I am sure of this because I have
done it and had no
problems with that part of the install. It's only if you want to
partition a new disk with
the intent of later installing an OS that does not support GPT.
-- 
R. Kevin Oberman, Network Engineer - Retired
E-mail: kob6558 at gmail.com