NFS.CONF(5) BSD File Formats Manual NFS.CONF(5)NAMEnfs.conf — The configuration file for NFS
SYNOPSISnfs.confDESCRIPTION
The nfs.conf file contains options used to specify NFS server and client
configuration and tuning.
Each line contains an option field and a value field, separated by an
equals character '='. For example:
some.nfs.option = value
Each line specifies a single option/value pair. Whitespace can be used
freely before and after fields. A hash character '#' begins a comment
that extends to the end of the line. Lines containing only whitespace or
comments are ignored. The file format is intended to be easily read
using functions like fparseln(3).
Values are typically integers. For options that enable/disable function‐
ality the value zero (0) indicates the option is off/disabled and the
value one (1) (or any other non-zero value) indicates the option is
on/enabled.
The options are:
nfs.client.access_cache_timeout
How long (in seconds) that access(2) information is cached. The
default is 60 seconds.
nfs.client.access_for_getattr
This option specifies if access(2) information should be oppor‐
tunistically fetched every time attributes are fetched. A
GETATTR request will only return attributes, but since ACCESS
requests usually also return current attributes, a single ACCESS
request may be used to fetch both access(2) information and
attributes. Enabling this may improve performance, but only if
the ACCESS check on the server is inexpensive. This may not be
the case with many modern operating systems. The default is 0
(off).
nfs.client.allow_async
Allow the use of the -o async mount option. This option must be
enabled in order for the async mount option to be honored
because (accidental) use of the async mount option may result in
data loss if the server crashes. The default is 0 (off).
nfs.client.callback_port
This option can be used to specify a port that the NFSv4 call‐
back RPC service should be available on. The default value is
unspecified, which means that any available port will be used.
nfs.client.initialdowndelay
When an NFS server is not responding, this option specifies how
long to wait (in seconds) before the initial notification is
posted. The default is 12 seconds.
nfs.client.iosize
This option specifies what size (in bytes) the NFS client
reports for the recommended I/O request size returned in stat(2)
and statfs(2) calls. The default value is 1048576 bytes.
nfs.client.mount.options
Mount options to be used for NFS file systems mounted via
mount(8) / mount_nfs(8). The value is in the same format as the
argument for the -o mount option (a comma-separated string of
options like: option1,option2=val,option3). The default value
is empty. These options are processed by mount_nfs(8) prior to
processing any other command-line options. Therefore, mount
options set in the NFS configuration file may be added to or
overriden by additional command-line options.
nfs.client.nextdowndelay
When an NFS server is not responding, this option specifies how
long to wait (in seconds) between notifications. The default is
30 seconds.
nfs.client.nfsiod_thread_max
The maximum number of NFS client asynchronous I/O (nfsiod)
threads to use. The default is 16.
nfs.client.statfs_rate_limit
The maximum number of times per second that an NFS client will
send a "statfs" RPC request to an NFS server to retrieve up-to-
date file system information. Requests for this information
that occur faster than this rate will receive cached values.
The default value is 10 times per second. A value of zero means
no limit.
nfs.client.is_mobile
This option specifies if an NFS client is on a mobile machine.
On a mobile machine, hard mounted file systems can be automati‐
cally forcibly unmounted if the following is met:
· The mount was automounted.
· The server is not responding.
· No files are open for writing.
· No files are memory mapped.
· There are no dirty pages associated with the mount.
The default for this option is to let the system detect this. A
non-zero value for this option treats this machine as a laptop
with respect to NFS behavior and allows automatic forcible
unmounting of unresponsive volumes described above. Conversely,
a zero value treats the machine as a desktop for traditional NFS
behavior, where hard mounts never time out. Setting a zero value
is useful for laptops that are being used as desktops.
nfs.lockd.grace_period
This option specifies the grace period (in seconds) during which
lockd will only accept requests from hosts which are reclaiming
locks which existed before the restart. The default value is 45
seconds.
nfs.lockd.host_monitor_cache_timeout
This option tells rpc.lockd how long (in seconds) to cache state
records for monitored hosts. Setting it to zero will disable
the cache which will make lock and unlock requests from a single
client more expensive because of additional interaction with the
client's statd. The default value is 60 seconds.
nfs.lockd.port
This option can be used to specify a port that the NFS LOCK ser‐
vice (lockd) should be available on. The default value is
unspecified, which means that any available port will be used.
nfs.lockd.send_using_tcp
This option tells lockd to use TCP sockets when contacting other
hosts. The default value is 0, which means lockd will use UDP.
nfs.lockd.send_using_mnt_transport
This option tells lockd to use the socket type of the corre‐
sponding nfs mount. Locking a file on a udp mount will use udp
and locking a file on a nfs mount mounted with tcp will use tcp.
Note that nfs.lockd.send_using_tcp will override this option.
The default value is 0, which means lockd will use UDP provided
nfs.lockd.send_using_tcp is not set or set to 0.
nfs.lockd.shutdown_delay_client
This option species how long (in seconds) the lockd daemon
should remain running after the unmounting of the last NFS file
system for which it may need to perform file locking requests.
The default value is 180 seconds. (Note: lockd may also remain
running if it is needed by the NFS server.)
nfs.lockd.shutdown_delay_server
This option species how long (in seconds) the lockd daemon
should remain running after the NFS server daemon, nfsd(8), is
stopped. The default value is 180 seconds. (Note: lockd may
also remain running if it is needed by any NFS file system
mounts.)
nfs.lockd.tcp
This option specifies whether the LOCK server should support
connections using TCP. The default value is 1 (enabled).
nfs.lockd.udp
This option specifies whether the LOCK server should support
connections using UDP. The default value is 1 (enabled).
nfs.lockd.verbose
This option controls how much logging lockd performs. It cur‐
rently maps directly to the rpc.lockd(8)-d debug_level option.
The default value is 0.
nfs.server.async
This option specifies that the NFS server should report unstable
writes as stable writes. The default is 0 (off). While
enabling this option can improve write performance, it will also
put data integrity at risk because the NFS client will be told
that data is on stable storage before it actually is. The data
may be lost if the NFS server crashes.
nfs.server.bonjour
This option controls whether the NFS service is advertised via
Bonjour. The default value is 1 (on).
nfs.server.bonjour.local_domain_only
This option controls whether the NFS service's Bonjour adver‐
tisement is restricted to the local domain only. The default
value is 0 (off).
nfs.server.export_hash_size
This option specifies the size of the NFS server export hash ta‐
ble. The default value is 64.
nfs.server.fsevents
This option controls whether the NFS server will generate fsev‐
ents for operations performed on an exported file system. The
default value is 1 (enabled).
nfs.server.mount.port
This option can be used to specify a port that the MOUNT service
(mountd) should be available on. The default value is unspeci‐
fied, which means that any available port will be used.
nfs.server.mount.regular_files
This option controls whether MOUNT requests for non-directory
objects will be allowed. The default value is 0 (off).
nfs.server.mount.require_resv_port
This option controls whether MOUNT requests are required to
originate from a reserved port (port < 1024). The default value
is 1 (yes). Many NFS server implementations require this
because of the false belief that this requirement increases
security.
nfs.server.nfsd_threads
This option controls how many NFS server (nfsd) threads are made
available to service NFS requests. The default value is 8.
nfs.server.port
This option can be used to specify a port that the NFS service
(nfsd) should be available on. The default value is 2049.
nfs.server.reqcache_size
This option specifies the size of the NFS server request cache.
The default value is 64.
nfs.server.request_queue_length
This option specifies the maximum number of NFS requests that
the NFS server can queue up internally on the NFS server's UDP
socket. The default value is 128. Note: using a large value
risks getting all the mbufs in the system placed on that queue
which can cause all networking to hang.
nfs.server.require_resv_port
This option controls whether NFS requests are required to origi‐
nate from a reserved port (port < 1024). The default value is 0
(no). Many NFS server implementations require this because of
the false belief that this requirement increases security.
nfs.server.rquota.port
This option can be used to specify a port that the RQUOTA ser‐
vice (rquotad) should be available on. The default value is
unspecified, which means that any available port will be used.
nfs.server.rquota.tcp
This option specifies whether the RQUOTA server should support
connections using TCP. The default value is 1 (enabled).
nfs.server.rquota.udp
This option specifies whether the RQUOTA server should support
connections using UDP. The default value is 1 (enabled).
nfs.server.tcp
This option specifies whether the NFS server should support con‐
nections using TCP. The default value is 1 (enabled).
nfs.server.udp
This option specifies whether the NFS server should support con‐
nections using UDP. The default value is 1 (enabled).
nfs.server.user_stats
This option controls whether the NFS server maintains active
user statistics. The default value is 1 (enabled).
nfs.server.verbose
This option controls how much logging nfsd performs. The
default value is 0 - where only messages up to priority
LOG_WARNING are logged. Setting the verbose level to 1 will add
LOG_NOTICE messages which includes logging failed mount
attempts. A verbose level of 2 will increase the log level to
LOG_INFO which includes logging successful mount attempts. A
log level of 3 or more will add LOG_DEBUG messages and cause
increasing amounts of debug information to be logged. nfsd's
verbose level can also be adjusted temporarily using the com‐
mand: nfsd verbose. Note: the syslog(8) configuration may need
to be adjusted in order to see the increased verbosity.
nfs.server.wg_delay
This option controls how long (in microseconds) NFSv2 writes
will be gathered up before being processed. The default value
is 1000. Setting this option to 0 will disable write gathering
for NFSv2.
nfs.server.wg_delay_v3
This option controls how long (in microseconds) NFSv3 writes
will be gathered up before being processed. The default value
is 0 (disabled). NFSv3's support of unstable writes effectively
eliminates the need for doing write gathering to increase per‐
formance.
nfs.statd.port
This option can be used to specify a port that the STATUS ser‐
vice (statd) should be available on. The default value is
unspecified, which means that any available port will be used.
nfs.statd.send_using_tcp
This option tells statd to use TCP sockets when contacting other
hosts. The default value is 0, which means statd will use UDP.
nfs.statd.simu_crash_allowed
This option controls whether statd allows SM_SIMU_CRASH
requests. The default value is 0 (not allowed).
nfs.statd.tcp
This option specifies whether the STATUS server should support
connections using TCP. The default value is 1 (enabled).
nfs.statd.udp
This option specifies whether the STATUS server should support
connections using UDP. The default value is 1 (enabled).
nfs.statd.verbose
This option controls how much logging statd performs. The
default value is 0.
FILES
/etc/nfs.conf The NFS configuration file.
SEE ALSOnfsd(8), rpc.lockd(8), rpc.rquotad(8), rpc.statd(8), mount_nfs(8)BSD July 21, 2009 BSD
