I ran into a strange automount issue where my NFS shares were not being mounted at boot time. nfs/client was enabled, my entry in /etc/vfstab was correct, and issuing a `mount -a` worked flawlessly. So what was the problem? Well, this was the entry in my vfstab file:
biff:/paulie    -       /export/home/paulie/biff   nfs
     -       yes     proto=tcp,vers=3
I wanted to place my NFS share inside a zfs filesystem so that it was easily accessible in my home directory.
[paulie@doc ~]$ zfs list | grep export/home/paulie
rpool/export/home/paulie  78M  2.82G  78M  /export/home/paulie
Turns out this is not such a good idea since the /etc/vfstab file is read *before* zpool's are imported and mounted. This means that all NFS shares need to be listed outside any filesystems to be mounted at boot time and then symlinked in.
[root@doc ~]# mkdir /biff
[paulie@doc ~]$ ln -s /biff/ /export/home/paulie/biff/
... and then changing around vfstab ...
biff:/paulie    -       /biff   nfs     -       
yes     proto=tcp,vers=3
And that's it, NFS should automount now:
[paulie@doc ~]$ df -kh | grep biff
biff:/paulie           2.7T   1.2T       1.4T    47%    /biff
Lesson learned.

posted by paulie
8:51 PST - January 3, 2012