https://docs.freebsd.org/en/books/handbook/network-servers/#network-nfs
rpcbind_enable="YES" rpcbind_flags="-s -l -h 192.168.0.100" nfs_server_enable="YES" nfs_server_flags="-u -t -n 6 -h 192.168.0.100" mountd_enable="YES" mountd_flags="-r" man rpcbind -h bindip -l Turn on libwrap connection logging. -s Cause rpcbind to change to the user daemon as soon as possible. This causes rpcbind to use non-privileged ports for outgoing con- nections, preventing non-privileged clients from using rpcbind to connect to services from a privileged port. man nfsd -h bindip For example, ``nfsd -u -t -n 6'' serves UDP and TCP transports using six daemons. man mountd -r Allow mount RPCs requests for regular files to be served. Although this seems to violate the mount protocol specification, some diskless workstations do mount requests for their swapfiles and expect them to be regular files. Since a regular file cannot be specified in /etc/exports, the entire file system in which the swapfiles resides will have to be exported with the -alldirs flag.
/etc/exports
FreeBSD で、リブートせずに /etc/exportsの変更を反映させる - Tamaのシステムメモ 2012
sudo /etc/rc.d/mountd reload
ファイルシステム内の細かい共有
複数のディレクトリの共有を行う際にハマりやすいポイントとして，ファイルシステムが同じ所のディレクトリの共有をかける場合，ディレクトリは一行に纏めて記載する必要がある．ということです．
FreeBSD で NFS (2) 【NFSサーバ設定と /etc/exports 詳解】 2014
sakashita-net.jp: FreeBSDでの/etc/exportsを書くときの注意 2017
mountd[13212]: -alldirs has multiple directories mountd[13212]: bad exports list line /usr/src /usr/obj -alldirs
複数ディレクトリと -alldirs を同時に指定できない
