$ cat localhost2.sh #!/bin/sh [ $# -eq 0 ] && localhost=127.0.0.1 [ $# -eq 1 ] && localhost=localhost uname -a ifconfig | grep inet [ -d /mnt2 ] || mkdir /mnt2 mount | grep -q mnt2 && umount /mnt2 mount | grep -q mnt && umount /mnt echo echo "tmpfs with no \"-o\" argument": mount -t tmpfs tmpfs /mnt echo "mount -t nfs -o retrycnt=1 $localhost:/mnt /mnt2" mount -t nfs -o retrycnt=1 $localhost:/mnt /mnt2 mount | grep mnt mount | grep -q mnt2 && umount /mnt2 mount | grep -q mnt && umount /mnt echo echo "Now with tmpfs, size=512m:" mount -t tmpfs -o "size=512m" tmpfs /mnt echo "mount -t nfs -o retrycnt=1 $localhost:/mnt /mnt2" mount -t nfs -o retrycnt=1 $localhost:/mnt /mnt2 mount | grep mnt mount | grep -q mnt2 && umount /mnt2 mount | grep -q mnt && umount /mnt $ ./localhost2.sh FreeBSD t2.osted.lan 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r315388M: Thu Mar 16 08:20:21 CET 2017 pho@t2.osted.lan:/usr/src/sys/amd64/compile/PHO amd64 inet 192.168.1.109 netmask 0xffffff00 broadcast 192.168.1.255 inet6 fe80::21e:67ff:fe56:b69b%igb0 prefixlen 64 scopeid 0x1 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3 inet 127.0.0.1 netmask 0xff000000 tmpfs with no "-o" argument: mount -t nfs -o retrycnt=1 127.0.0.1:/mnt /mnt2 tmpfs on /mnt (tmpfs, local) 127.0.0.1:/mnt on /mnt2 (nfs) Now with tmpfs, size=512m: mount -t nfs -o retrycnt=1 127.0.0.1:/mnt /mnt2 [tcp] 127.0.0.1:/mnt: Permission denied tmpfs on /mnt (tmpfs, local) $