Using the showmount Command

This command lists all clients and the local directories that they have mounted.

# showmount -a bee
lilac:/export/share/man
lilac:/usr/src
rose:/usr/src
tulip:/export/share/man

This command lists the directories that have been mounted.

# showmount -d bee
/export/share/man
/usr/src

This command lists file systems that have been shared.

# showmount -e bee
/usr/src								(everyone)
/export/share/man					eng

setmnt

This command creates an /etc/mnttab table. The mount and umount commands consult the table. Generally, you do not have to run this command manually, as it runs automatically when a system is booted.

Other Useful Commands

These commands can be useful when troubleshooting NFS problems.

nfsstat

You can use this command to gather statistical information about NFS and RPC connections. The syntax of the command is as follows:

nfsstat [ -cmnrsz ]

If no options are supplied on the command line, the -cnrs options are used.

Gathering server-side statistics can be important for debugging problems when new software or hardware is added to the computing environment. Running this command a minimum of once a week, and storing the numbers, provides a good history of previous performance.

Using the nfsstat Command

# nfsstat -s

Server rpc:
Connection oriented:
calls      badcalls   nullrecv   badlen      xdrcall    dupchecks  dupreqs
11420263   0          0          0           0          1428274    19
Connectionless:
calls      badcalls   nullrecv   badlen      xdrcall    dupchecks  dupreqs
14569706   0          0          0           0          953332     1601

Server nfs:
calls      badcalls
24234967   226
Version 2: (13073528 calls)
null       getattr    setattr    root        lookup     readlink   read
138612 1%  1192059 9% 45676 0%   0 0%        9300029 71% 9872 0%   1319897 10%
wrcache    write      create     remove      rename     link       symlink
0 0%       805444 6%  43417 0%   44951 0%    3831 0%    4758 0%    1490 0%
mkdir      rmdir      readdir    statfs
2235 0%    1518 0%    51897 0%   107842 0%
Version 3: (11114810 calls)
null       getattr    setattr    lookup      access     readlink   read
141059 1%  3911728 35% 181185 1% 3395029 30% 1097018 9% 4777 0%   960503 8%
write      create     mkdir      symlink     mknod      remove     rmdir
763996 6%  159257 1%  3997 0%    10532 0%    26 0%      164698 1%  2251 0%
rename     link       readdir    readdirplus fsstat     fsinfo     pathconf
53303 0%   9500 0%    62022 0%   79512 0%    3442 0%    34275 0%   3023 0%
commit    
73677 0%  

Server nfs_acl:
Version 2: (1579 calls)
null       getacl     setacl     getattr     access    
0 0%       3 0%       0 0%       1000 63%    576 36%   
Version 3: (45318 calls)
null       getacl     setacl    
0 0%       45318 100% 0 0%

The previous listing is an example of NFS server statistics. The first five lines relate to RPC and the remaining lines report NFS activities. In both sets of statistics, knowing the average number of badcalls or calls and the number of calls per week can help identify a problem. The badcalls value reports the number of bad messages from a client. This value can point out network hardware problems.

Some of the connections generate write activity on the disks. A sudden increase in these statistics could indicate trouble and should be investigated. For NFS version 2 statistics, the connections to note are setattr, write, create, remove, rename, link, symlink, mkdir, and rmdir. For NFS version 3 statistics, the value to watch is commit. If the commit level is high in one NFS server as compared to another almost identical server, check that the NFS clients have enough memory. The number of commit operations on the server grows when clients do not have available resources.

pstack

This command displays a stack trace for each process. The pstack command must be run by the owner of the process or by root. You can use pstack to determine where a process is hung. The only option that is allowed with this command is the PID of the process that you want to check (see the proc(1) man page).

The following example is checking the nfsd process that is running.

# /usr/proc/bin/pstack 243
243:    /usr/lib/nfs/nfsd -a 16
 ef675c04 poll     (24d50, 2, ffffffff)
 000115dc ???????? (24000, 132c4, 276d8, 1329c, 276d8, 0)
 00011390 main     (3, efffff14, 0, 0, ffffffff, 400) + 3c8
 00010fb0 _start   (0, 0, 0, 0, 0, 0) + 5c

The example shows that the process is waiting for a new connection request. This is a normal response. If the stack shows that the process is still in poll after a request is made, the process might be hung. Follow the instructions in "How to Restart NFS Services" to fix this problem. Review the instructions in "NFS Troubleshooting Procedures" to fully verify that your problem is a hung program.

rpcinfo

This command generates information about the RPC service that is running on a system. You can also use it to change the RPC service. Many options are available with this command (see the rpcinfo(1M) man page). This is a shortened synopsis for some of the options that you can use with the command:

rpcinfo [ -m | -s ] [ hostname ]

rpcinfo -T transport hostname [ progname ]

rpcinfo [ -t | -u ] [ hostname ] [ progname ]

If no value is given for hostname, the local host name is used. You can substitute the RPC program number for progname, but many users can remember the name and not the number. You can use the -p option in place of the -s option on those systems that do not run the NFS version 3 software.

The data that is generated by this command can include the following:

• The RPC program number

• The version number for a specific program

• The transport protocol that is being used

• The name of the RPC service

• The owner of the RPC service