NFSv4 服务器启动需要更多时间

Question

我正在尝试仅为版本 4 启动 nfsd 守护进程。需要 2.30 多分钟才能启动。

# time /usr/sbin/rpc.nfsd -d -N 2 -N 3 -V 4.1 8
rpc.nfsd: knfsd is currently down
rpc.nfsd: Writing version string to kernel: -2 -3 +4 +4.1
rpc.nfsd: Created AF_INET TCP socket.

<<< hangs here for more than 2 mins >>>

rpc.nfsd: Created AF_INET6 TCP socket.

real    2m36.016s
user    0m0.001s
sys 0m0.003s

当我用 strace 运行它时，我可以看到它正在等待套接字写入调用（）。

socket(AF_INET, SOCK_STREAM, IPPROTO_TCP) = 4
write(2, "rpc.nfsd: ", 10rpc.nfsd: )              = 10
write(2, "Created AF_INET TCP socket.", 27Created AF_INET TCP socket.) = 27
write(2, "\n", 1
)                       = 1
setsockopt(4, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
bind(4, {sa_family=AF_INET, sin_port=htons(2049), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
listen(4, 64)                           = 0
write(3, "4\n", 2


<<< waiting here for more than 2 mins >>>


)                      = 2
close(3)                                = 0
close(4)                                = 0

有人可以帮助找到根本原因并解决它吗？

更新：当我在 rpc.nfsd 之前启用并启动 rpcbind 服务时，问题得到解决。为什么 NFSv4 需要 rpcbind 服务？