RootFile System Error

[M. Warner Losh]

In message: <4C408821.8070403 at exonetric.com>
            Mark Blackman <mark at exonetric.com> writes:
: Ravindra wrote:
: > it is larger than 4 MB, but still i am unable.
: >
: 
: I'm guessing that MFD_ROOT_SIZE=4MB constrains the
: total size of the root filesystem. The root filesystem
: you've built is too big to fit into 4MB. I've no idea
: if you can increase MFD_ROOT_SIZE to accomodate the
: root file system you've built *OR* if you need to strip
: your root file system down.

MFD_ROOT_SIZE does do exactly that.  It says 'reserve exactly this
amount of space for a MFS root inside the kernel image'.  If you try
to add a MFS root that's larger, it will fail as seen above.

250MB is also really large for a ram disk.  I'm not familiar with the
limitations of ARM, but I know that for MIPS this would be 1/2 of the
available KVM space and it likely wouldn't cope too well with that.
IIRC, there's a kernel size limit of 32MB on ARM, which would
constrain the ram disk size to something less than that.

How are you building the root image?  If it is following my
instructions using buildworld, chances are it is too bloated.  You'd
be better off with a nanobsd image, which would be much smaller (like
on the order of 20-30MB if you turn everything off, and maybe do some
hand/script pruning of files at the end).

Warner

P.S.  Sorry for the zen-master-like replies earlier.  I realized later
I should have explained why this was a problem.