option.
.TP 1.5i
.BI timeo= n
-The time (in tenths of a second) the NFS client waits for a
-response before it retries an NFS request. If this
-option is not specified, requests are retried every
-60 seconds for NFS over TCP.
-The NFS client does not perform any kind of timeout backoff
-for NFS over TCP.
+The time in deciseconds (tenths of a second) the NFS client waits for a
+response before it retries an NFS request.
+.IP
+For NFS over TCP the default
+.B timeo
+value is 600 (60 seconds).
+The NFS client performs linear backoff: After each retransmission the
+timeout is increased by
+.BR timeo
+up to the maximum of 600 seconds.
.IP
However, for NFS over UDP, the client uses an adaptive
algorithm to estimate an appropriate timeout value for frequently used
.BR krb5p ,
.BR lkey ,
.BR lkeyi ,
-.BR lkeyp ,
-.BR spkm ,
-.BR spkmi ,
and
-.BR spkmp .
+.BR lkeyp ,
Refer to the SECURITY CONSIDERATIONS section for details.
.TP 1.5i
.BR sharecache " / " nosharecache
to prevent data exposure during network transit; however,
expect some performance impact
when using integrity checking or encryption.
-Similar support for other forms of cryptographic security (such as lipkey and SPKM3)
+Similar support for other forms of cryptographic security (such as lipkey)
is also available.
.P
The NFS version 4 protocol allows
specify either the local mount directory, or the server hostname and
export pathname, but not both, during a remount. For example,
.P
-.NF
-.TA 2.5i
+.nf
+.ta 8n
mount -o remount,ro /mnt
-.FI
+.fi
.P
merges the mount option
.B ro