The mount command example in section 36.19.4.1 should mount using mgs@tcp instead of mds@tcp

36.19.4.1. Example
$ mount -t lustre -o flock mds@tcp0:/lustre /mnt/client
You can check it in /etc/mtab. It should look like,
mds@tcp0:/lustre /mnt/client lustre rw,flock 0 0