Another interesting issue here which I really think puts the nail in
coffin is that we really want to be able to use more complex access
schemes, such as vinum, for these large filesystems. I don't want to
have to depend on something like the BIOS fake-raid, its just too severely
limiting.
With a small UFS /boot we can make the primary root filesystem whatever
we want... from multi-volume mounts to vinum or any other scheme we
choose, including eventually mounts named by serial number.
The more I think about it, the more I really want us to default to
a small UFS /boot. Here's another example... lets say we wanted to
support encrypted disks. The information on the UFS /boot would not
have to be encrypted per-say, since it's just a tiny boot-only partition
containing no production data. It could, however, contain sufficient
information to allow the system to auto-boot the encrypted root disk.
For example, the /boot booted kernel could query the local environment,
such as the network, and acquire sufficient information to mount its
encrypted root.
--
If we reserved space for a /boot by default on every disk we disklabel,
it could lead to some fairly impressive booting and recovery options.
I'd like it to be the new concept for the 'a' partition. Make 'a'
*always* be a small /boot partition.
-Matt