嵌入式 Linux NFS 挂载失败 |

CMDLINE_VALUE = "mem=64M console=ttyS0,115200 init=/init root=/dev/nfs rw nfsroot=192.168.111.238:/opt/nfs,v3,proto=tcp,nolock,rsize=4096,wsize=4096,intr ip=192.168.111.239:::255.255.254.0"

Error

nfs: server 192.168.111.238 not responding, still trying

Fixed

因为NFS默认采用UDP进行传输中途容易丢包，所以修改成TCP进行传输问题解决

proto=tcp

This is a problem with NFS and 2.6 kernels, fast server NICs and
comparatively slower client NICs. This will show up when the server has
a 1000Mb card and the client a 100Mb, or when the server has a 100Mb
card and the client a 10Mb.

rsize=4096,wsize=4096

通过设定大的同时传输的数据块大小(bytes)，以提高NFS读写的速度。改变这些值时要当心，一些旧的linux内核和网卡在大的块大小不能正常工作

nfsroot.c

Linux Kernel 2.6 nfsroot支持的参数：

nfsroot=xxx

static match_table_t __initdata tokens = {                                    
    {Opt_port, "port=%u"},                                                    
    {Opt_rsize, "rsize=%u"},                                                  
    {Opt_wsize, "wsize=%u"},                                                  
    {Opt_timeo, "timeo=%u"},                                                  
    {Opt_retrans, "retrans=%u"},                                              
    {Opt_acregmin, "acregmin=%u"},                                            
    {Opt_acregmax, "acregmax=%u"},                                                                                                 
    {Opt_acdirmin, "acdirmin=%u"},                                            
    {Opt_acdirmax, "acdirmax=%u"},                                            
    {Opt_soft, "soft"},                                                       
    {Opt_hard, "hard"},                                                       
    {Opt_intr, "intr"},                                                       
    {Opt_nointr, "nointr"},                                                   
    {Opt_posix, "posix"},                                                     
    {Opt_noposix, "noposix"},                                                 
    {Opt_cto, "cto"},                                                         
    {Opt_nocto, "nocto"},                                                     
    {Opt_ac, "ac"},                                                           
    {Opt_noac, "noac"},                                                       
    {Opt_lock, "lock"},                                                       
    {Opt_nolock, "nolock"},                                                   
    {Opt_v2, "nfsvers=2"},                                                    
    {Opt_v2, "v2"},                                                           
    {Opt_v3, "nfsvers=3"},         
    {Opt_v3, "v3"},                                                           
    {Opt_udp, "proto=udp"},                                                   
    {Opt_udp, "udp"},                                                         
    {Opt_tcp, "proto=tcp"},                                                   
    {Opt_tcp, "tcp"},                                                         
    {Opt_acl, "acl"},                                                         
    {Opt_noacl, "noacl"},                                                     
    {Opt_err, NULL}                                                           
};

服务依赖

错误如下：

user:~ # sudo mount -t nfs -o rw 10.9.87.65:/filedir /filedir
mount.nfs: rpc.statd is not running but is required for remote locking.
mount.nfs: Either use '-o nolock' to keep locks local, or start statd.
mount.nfs: Operation not permitted

nfs mount 默认选项包括文件锁，依赖于 portmap 提供的动态端口分配功能或者是没有启动 rpcbind 服务

mount -o nolock

# sudo mount -t nfs -o rw,nolock 10.9.87.65:/filedir /filedir

启动 server

$ sudo service nfslock restart
$ sudo service rpcbind restart
$ sudo service nfs restart

查看状态

查看支持版本

$ sudo cat /proc/fs/nfsd/versions
-2 +3 +4 +4.1 +4.2

修改 /etc/default/nfs-kernel-server，在文件末尾加入一句：RPCNFSDOPTS="--nfs-version 2,3,4 --debug --syslog" 以支持 v2

查看 nfs 状态

$ nfsstat -s
$ nfsstat -c

挂载测试

$ mount -t nfs -o vers=4 192.168.1.10:/mnt/data /data
$ mount -t nfs -o vers=3 192.168.1.10:/mnt/data /data

查看 mount 状态

$ showmount -e 192.168.110.55
$ mount

Error

Fixed

nfsroot.c

服务依赖

查看状态

Ref