When tried to run a lock test, the following error is seen in the dmesg of the client. And the lock test just blocks.

nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                                                                                                                   
nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                                                                                                                   
nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                                                                                                                   
nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                                                                                                                   
nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                                                                                                                   
nfs server 192.168.1.77:/nfs-multi-client: lockd not responding                 

Nothing is seen in the nfs logs, absolutely nothing at all. Other file operations work just fine.


mac:nfs1 root# cat test1.c 
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <err.h>
#include <sysexits.h>
#include <sys/param.h>

int
main(void)
{
       int fd, i, fi;
       struct flock fl;
       char fpath[MAXPATHLEN + 1];

       if ((fd = open("foo.txt", O_CREAT|O_WRONLY|O_APPEND, 0)) == -1)
               err(EX_OSERR, "open failed");

       fl.l_start = 0;
       fl.l_len = 0;
       fl.l_whence = SEEK_SET;
       fl.l_type = F_WRLCK;
       if (fcntl(fd, F_SETLKW, &fl) == -1)
               err(EX_OSERR, "fcntl failed");

       return 0;       
}