NFSRoot pxe available disk space

[Rick Macklem]

> I am running FreeBSD 9 amd64 via pxe NFSRoot
> I get a negative value for my available space on /
> 
> my FreeBSD NFS server is also running FreeBSD 9 built from todays SVN
> sources
> this did not happen in FreeBSD 8.1
> 
> 
> Sam# uname -a
> FreeBSD Sam.PuffyBSD.Com 9.0-CURRENT FreeBSD 9.0-CURRENT #2: Thu Sep
> 23 18:24:25 CDT 2010
> root at FNFS.PuffyBSD.Com:/usr/obj/usr/src/sys/WORKSTATION amd64
> 
> 
> Sam# df -h
> Filesystem Size Used
> Avail Capacity Mounted on
> 192.168.8.10:/Network/pxe/FreeBSD_AMD64_CURRENT -807G 28G
> -834G -3% /
> devfs 1.0K 1.0K
> 0B 100% /dev
> tmpfs 218M 4.0K
> 218M 0% /tmp
> linprocfs 4.0K 4.0K
> 0B 100% /compat/linux/proc
> 192.168.8.10:/Network/distfiles 1.2T 26G
> 1.2T 2% /usr/ports/distfiles
> 192.168.8.10:/Network/tv 1.5T 373G
> 1.2T 24% /Network/tv
> 192.168.8.10:/Network/iso 1.5T 277G
> 1.2T 19% /Network/iso
> 192.168.8.10:/Network/wow 1.2T 35G
> 1.2T 3% /Network/wow
> 192.168.8.10:/Network/music 1.3T 106G
> 1.2T 8% /Network/music
> 192.168.8.10:/Network/public 1.3T 148G
> 1.2T 11% /Network/public
> 192.168.8.10:/Network/pxe/FreeBSD_i386_8_1 1.2T 4.4G
> 1.2T 0% /compat/FreeBSD-i386
> 192.168.8.10:/Network/home/sfourman 1.2T 33G
> 1.2T 3% /usr/home/sfourman
> 
> 
I did send out a heads up when I committed it. If you replace the
kernel, but not pxeboot (built from recent sources), then the
default reverts back to using NFSv2. Either add "nfsv3" as an
option for the "/" line in /etc/fstab for the root fs on the NFS
server or replace "pxeboot" with one built from recent sources.
I think this is probably what is causing it.

rick
ps: NFSv2 only used 32bit #s for the sizes, so an overflow
    can easily happen.