确认host端的nfs支持的版本，使用命令nfsstat查看
rzx@rzx-desktop:~$ nfsstat
Server rpc stats:
calls badcalls badfmt badauth badclnt
12242 41 41 0 0
Server nfs v3:
null getattr setattr lookup access
4 0% 1787 14% 29 0% 1542 12% 706 5%
readlink read write create mkdir
244 1% 5579 45% 2173 17% 14 0% 4 0%
symlink mknod remove rmdir rename
1 0% 0 0% 1 0% 0 0% 12 0%
link readdir readdirplus fsstat fsinfo
0 0% 0 0% 112 0% 20 0% 8 0%
pathconf commit
4 0% 2 0%
在bootargs中指定版本console=ttymxc1,115200 root=/dev/nfs rw nfsroot=192.168.0.105:/home/rzx/work/nfs,v3 ip=192.168.0.107:192.168.0.105:192.168.0.1:255.255.255.0::eth0:off
VFS: Cannot open root device "nfs" or unknown-block(2,0): error -6
原文：https://www.cnblogs.com/-rzx-/p/12264901.html