Instead of a textual option string, parsed by the kernel, the nfs file system expects a binary argument of type struct nfs_mount_data. The program mount itself parses the following options of the form 'tag=value', and puts them in the structure mentioned: rsize=n, wsize=n, timeo=n, retrans=n, acregmin=n, acregmax=n, acdirmin=n, acdirmax=n, actimeo=n, retry=n, port=n, mountport=n, mounthost=name, mountprog=n, mountvers=n, nfsprog=n, nfsvers=n, namlen=n. The option addr=n is accepted but ignored. Also the following Boolean options, possibly preceded by no are recognized: bg, fg, soft, hard, intr, posix, cto, ac, tcp, udp, lock. For details, see nfs(5).
Especially useful options include
Instead of a textual option string, parsed by the kernel, the nfs4 file system expects a binary argument of type struct nfs4_mount_data. The program mount itself parses the following options of the form 'tag=value', and puts them in the structure mentioned: rsize=n, wsize=n, timeo=n, retrans=n, acregmin=n, acregmax=n, acdirmin=n, acdirmax=n, actimeo=n, retry=n, port=n, proto=n, clientaddr=n, sec=n. The option addr=n is accepted but ignored. Also the following Boolean options, possibly preceded by no are recognized: bg, fg, soft, hard, intr, cto, ac, For details, see nfs(5).
Especially useful options include