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mongod
mongod
¶
Synopsis¶
mongod
is the primary daemon process for the MongoDB
system. It handles data requests, manages data access, and performs
background management operations.
This document provides a complete overview of all command line options
for mongod
. These command line options are primarily useful
for testing: In common operation, use the configuration file
options to control the behavior of
your database.
Options¶
-
mongod
¶
Core Options¶
-
--help
,
-h
¶
Returns information on the options and use of mongod.
-
--version
¶
Returns the mongod release number.
-
--config
<filename>
,
-f
<filename>
¶ Specifies a configuration file for runtime configuration options. The configuration file is the preferred method for runtime configuration of mongod. The options are equivalent to the command-line configuration options. See Configuration File Options for more information.
Ensure the configuration file uses ASCII encoding. The mongod instance does not support configuration files with non-ASCII encoding, including UTF-8.
-
--verbose
,
-v
¶
Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the
-v
form by including the option multiple times, (e.g.-vvvvv
.)
-
--quiet
¶
Runs the mongod in a quiet mode that attempts to limit the amount of output.
This option suppresses:
- output from database commands
- replication activity
- connection accepted events
- connection closed events
-
--port
<port>
¶ Default: 27017
Specifies the TCP port on which the MongoDB instance listens for client connections.
-
--bind_ip
<ip address>
¶ Default: All interfaces.
Changed in version 2.6.0: The
deb
andrpm
packages include a default configuration file (/etc/mongod.conf
) that sets--bind_ip
to127.0.0.1
.The IP addresses and/or full Unix domain socket paths on which mongod should listen for client connections. You may attach mongod to any interface. To bind to multiple addresses, enter a list of comma-separated values.
Example
localhost,/tmp/mongod.sock
You can specify both IPv4 and IPv6 addresses, or hostnames that resolve to an IPv4 or IPv6 address.
Example
localhost, 2001:0DB8:e132:ba26:0d5c:2774:e7f9:d513
Note
If specifying an IPv6 address or a hostname that resolves to an IPv6 address to
--bind_ip
, you must start mongod with--ipv6
to enable IPv6 support. Specifying an IPv6 address to--bind_ip
does not enable IPv6 support.If specifying a link-local IPv6 address (
fe80::/10
), you must append the zone index to that address (i.e.fe80::<address>%<adapter-name>
).Example
localhost,fe80::a00:27ff:fee0:1fcf%enp0s3
Tip
To avoid downtime, give each config server a logical DNS name (unrelated to the server’s physical or virtual hostname). Without logical DNS names, moving or renaming a config server requires shutting down every
mongod
andmongos
instance in the sharded cluster.Warning
Before binding to a non-localhost (e.g. publicly accessible) IP address, ensure you have secured your cluster from unauthorized access. For a complete list of security recommendations, see Security Checklist. At minimum, consider enabling authentication and hardening network infrastructure.
To bind to all IPv4 addresses, enter
0.0.0.0
.To bind to all IPv4 and IPv6 addresses, enter
0.0.0.0,::
.
-
--ipv6
¶
Enables IPv6 support. mongod disables IPv6 support by default.
Setting
--ipv6
does not direct the mongod to listen on any local IPv6 addresses or interfaces. To configure the mongod to listen on an IPv6 interface, you must configure--bind_ip
with one or more IPv6 addresses or hostnames that resolve to IPv6 addresses.
-
--maxConns
<number>
¶ The maximum number of simultaneous connections that mongod will accept. This setting has no effect if it is higher than your operating system’s configured maximum connection tracking threshold.
Do not assign too low of a value to this option, or you will encounter errors during normal application operation.
Note
Changed in version 2.6: MongoDB removed the upward limit on the
maxIncomingConnections
setting.
-
--logpath
<path>
¶ Sends all diagnostic logging information to a log file instead of to standard output or to the host’s syslog system. MongoDB creates the log file at the path you specify.
By default, MongoDB will move any existing log file rather than overwrite it. To instead append to the log file, set the
--logappend
option.
-
--syslog
¶
Sends all logging output to the host’s syslog system rather than to standard output or to a log file. , as with
--logpath
.The
--syslog
option is not supported on Windows.
-
--syslogFacility
<string>
¶ Default: user
Specifies the facility level used when logging messages to syslog. The value you specify must be supported by your operating system’s implementation of syslog. To use this option, you must enable the
--syslog
option..
-
--logappend
¶
Appends new entries to the end of the existing log file when the mongod instance restarts. Without this option,
mongod
will back up the existing log and create a new file.
-
--logRotate
<string>
¶ Default: rename
New in version 3.0.0.
Determines the behavior for the
logRotate
command. Specify eitherrename
orreopen
:rename
renames the log file.reopen
closes and reopens the log file following the typical Linux/Unix log rotate behavior. Usereopen
when using the Linux/Unix logrotate utility to avoid log loss.If you specify
reopen
, you must also use--logappend
.
-
--timeStampFormat
<string>
¶ Default: iso8601-local
The time format for timestamps in log messages. Specify one of the following values:
Value Description ctime
Displays timestamps as Wed Dec 31 18:17:54.811
.iso8601-utc
Displays timestamps in Coordinated Universal Time (UTC) in the ISO-8601 format. For example, for New York at the start of the Epoch: 1970-01-01T00:00:00.000Z
iso8601-local
Displays timestamps in local time in the ISO-8601 format. For example, for New York at the start of the Epoch: 1969-12-31T19:00:00.000-0500
-
--pidfilepath
<path>
¶ Specifies a file location to hold the process ID of the mongod process where mongod will write its PID. This is useful for tracking the mongod process in combination with the the
--fork
option. Without a specified--pidfilepath
option, the process creates no PID file.
-
--keyFile
<file>
¶ Specifies the path to a key file that stores the shared secret that MongoDB instances use to authenticate to each other in a sharded cluster or replica set.
--keyFile
implies--auth
. See Internal Authentication for more information.
-
--setParameter
<options>
¶ Specifies one of the MongoDB parameters described in MongoDB Server Parameters. You can specify multiple
setParameter
fields.
-
--httpinterface
¶
Deprecated since version 3.2: HTTP interface for MongoDB
Enables the HTTP interface. Enabling the interface can increase network exposure.
Leave the HTTP interface disabled for production deployments. If you do enable this interface, you should only allow trusted clients to access this port. See Firewalls.
Note
- While MongoDB Enterprise does support Kerberos authentication, Kerberos is not supported in HTTP status interface in any version of MongoDB.
New in version 2.6.
-
--nounixsocket
¶
Disables listening on the UNIX domain socket.
--nounixsocket
applies only to Unix-based systems.The mongod process always listens on the UNIX socket unless one of the following is true:
--nounixsocket
is setnet.bindIp
is not setnet.bindIp
does not specify127.0.0.1
-
--unixSocketPrefix
<path>
¶ Default: /tmp
The path for the UNIX socket.
--unixSocketPrefix
applies only to Unix-based systems.If this option has no value, the mongod process creates a socket with
/tmp
as a prefix. MongoDB creates and listens on a UNIX socket unless one of the following is true:net.unixDomainSocket.enabled
isfalse
--nounixsocket
is setnet.bindIp
is not setnet.bindIp
does not specify127.0.0.1
-
--filePermissions
<path>
¶ Default:
0700
Sets the permission for the UNIX domain socket file.
--filePermissions
applies only to Unix-based systems.
-
--fork
¶
Enables a daemon mode that runs the mongod process in the background. By default mongod does not run as a daemon: typically you will run mongod as a daemon, either by using
--fork
or by using a controlling process that handles the daemonization process (e.g. as withupstart
andsystemd
).The
--fork
option is not supported on Windows.
-
--auth
¶
Enables authorization to control user’s access to database resources and operations. When authorization is enabled, MongoDB requires all clients to authenticate themselves first in order to determine the access for the client.
Configure users via the mongo shell. If no users exist, the localhost interface will continue to have access to the database until you create the first user.
See Security for more information.
-
--noauth
¶
Disables authentication. Currently the default. Exists for future compatibility and clarity.
-
--jsonp
¶
Permits JSONP access via an HTTP interface. Enabling the interface can increase network exposure. The
--jsonp
option enables the HTTP interface, even if theHTTP interface
option is disabled.Deprecated since version 3.2: HTTP interface for MongoDB
-
--rest
¶
Enables the simple REST API. Enabling the REST API enables the HTTP interface, even if the
HTTP interface
option is disabled, and as a result can increase network exposure.Deprecated since version 3.2: HTTP interface for MongoDB
-
--slowms
<integer>
¶ Default: 100
The threshold in milliseconds at which the database profiler considers a query slow. MongoDB records all slow queries to the log, even when the database profiler is off. When the profiler is on, it writes to the
system.profile
collection. See theprofile
command for more information on the database profiler.
-
--profile
<level>
¶ Default: 0
Changes the level of database profiling, which inserts information about operation performance into the
system.profile
collection. Specify one of the following levels:Level Setting 0 Off. No profiling. 1 On. Only includes slow operations. 2 On. Includes all operations. Database profiling can impact database performance. Enable this option only after careful consideration.
-
--cpu
¶
Forces the mongod process to report the percentage of CPU time in write lock, every four seconds.
-
--sysinfo
¶
Returns diagnostic system information and then exits. The information provides the page size, the number of physical pages, and the number of available physical pages.
-
--noscripting
¶
Disables the scripting engine.
-
--notablescan
¶
Forbids operations that require a collection scan. See
notablescan
for additional information.
-
--shutdown
¶
The
--shutdown
option cleanly and safely terminates the mongod process. When invoking mongod with this option you must set the--dbpath
option either directly or by way of the configuration file and the--config
option.The
--shutdown
option is available only on Linux systems.
Storage Options¶
-
--storageEngine
string
¶ Default:
wiredTiger
New in version 3.0.
Changed in version 3.2: Starting in MongoDB 3.2,
wiredTiger
is the default.Specifies the storage engine for the mongod database. Available values include:
Value Description mmapv1
To specify the MMAPv1 Storage Engine. wiredTiger
To specify the WiredTiger Storage Engine. inMemory
To specify the In-Memory Storage Engine.
New in version 3.2: Available in MongoDB Enterprise only.
If you attempt to start a mongod with a
--dbpath
that contains data files produced by a storage engine other than the one specified by--storageEngine
, mongod will refuse to start.
-
--dbpath
<path>
¶ Default:
/data/db
on Linux and macOS,\data\db
on WindowsThe directory where the mongod instance stores its data.
If you installed MongoDB using a package management system, check the
/etc/mongod.conf
file provided by your packages to see the directory is specified.Changed in version 3.0: The files in
--dbpath
must correspond to the storage engine specified in--storageEngine
. If the data files do not correspond to--storageEngine
, mongod will refuse to start.
-
--directoryperdb
¶
Uses a separate directory to store data for each database. The directories are under the
--dbpath
directory, and each subdirectory name corresponds to the database name.Changed in version 3.0: To change the
--directoryperdb
option for existing deployments, you must restart themongod
instances with the new--directoryperdb
value and a new data directory (--dbpath <new path>
), and then repopulate the data.- For standalone instances, you can use
mongodump
on the existing instance, stop the instance, restart with the new--directoryperdb
value and a new data directory, and usemongorestore
to populate the new data directory. - For replica sets, you can update in a rolling manner by stopping
a secondary member, restart with the new
--directoryperdb
value and a new data directory, and use initial sync to populate the new data directory. To update all members, start with the secondary members first. Then step down the primary, and update the stepped-down member.
Not available for
mongod
instances that use the in-memory storage engine.- For standalone instances, you can use
-
--noIndexBuildRetry
¶
Stops the mongod from rebuilding incomplete indexes on the next start up. This applies in cases where the mongod restarts after it has shut down or stopped in the middle of an index build. In such cases, the mongod always removes any incomplete indexes, and then also, by default, attempts to rebuild them. To stop the mongod from rebuilding incomplete indexes on start up, include this option on the command-line.
Not available for
mongod
instances that use the in-memory storage engine.
-
--noprealloc
¶
Deprecated since version 2.6: By default, MongoDB does not preallocate data files. The option exists for compatibility and clarity.
Disables the preallocation of data files.
-
--nssize
<value>
¶ Default: 16
Specifies the default size for namespace files, which are files that end in
.ns
. Each collection and index counts as a namespace.Use this setting to control size for newly created namespace files. This option has no impact on existing files. The maximum size for a namespace file is 2047 megabytes. The default value of 16 megabytes provides for approximately 24,000 namespaces.
-
--quota
¶
Enables a maximum limit for the number data files each database can have. When running with the
--quota
option, MongoDB has a maximum of 8 data files per database. Adjust the quota with--quotaFiles
.
-
--quotaFiles
<number>
¶ Default: 8
Modifies the limit on the number of data files per database.
--quotaFiles
option requires that you set--quota
.
-
--smallfiles
¶
Sets MongoDB to use a smaller default file size. The
--smallfiles
option reduces the initial size for data files and limits the maximum size to 512 megabytes.--smallfiles
also reduces the size of each journal file from 1 gigabyte to 128 megabytes. Use--smallfiles
if you have a large number of databases that each holds a small quantity of data.The
--smallfiles
option can lead the mongod instance to create a large number of files, which can affect performance for larger databases.
-
--syncdelay
<value>
¶ Default: 60
Controls how much time can pass before MongoDB flushes data to the data files via an fsync operation.
Do not set this value on production systems. In almost every situation, you should use the default setting.
Warning
If you set
--syncdelay
to0
, MongoDB will not sync the memory mapped files to disk.The mongod process writes data very quickly to the journal and lazily to the data files.
--syncdelay
has no effect on thejournal
files or journaling, but if--syncdelay
is set to0
the journal will eventually consume all available disk space. If you set--syncdelay
to0
for testing purposes, you should also set--nojournal
totrue
.The
serverStatus
command reports the background flush thread’s status via thebackgroundFlushing
field.Not available for
mongod
instances that use the in-memory storage engine.
-
--upgrade
¶
Upgrades the on-disk data format of the files specified by the
--dbpath
to the latest version, if needed.This option only affects the operation of the mongod if the data files are in an old format.
In most cases you should not set this value, so you can exercise the most control over your upgrade process. See the MongoDB release notes (on the download page) for more information about the upgrade process.
-
--repair
¶
Runs a repair routine on all databases. This is equivalent to shutting down and running the
repairDatabase
database command on all databases.Warning
- Before using
repairDatabase
, make a backup copy of the dbpath directory. - Avoid running
repairDatabase
against a replica set. If you are trying to repair a replica set member, and you have access to an intact copy of your data (e.g. a recent backup or an intact member of the replica set), you should restore from that intact copy (see Resync a Member of a Replica Set), and not userepairDatabase
. - Only use the
repairDatabase
command and associated wrappers, includingdb.repairDatabase()
andmongod --repair
, if you have no other options. These operations remove and do not save any corrupt data during the repair process.
If you are running with journaling enabled, there is almost never any need to run
repairDatabase
unless you need to recover from a disk-level data corruption. In the event of an unclean shutdown, the server will be able to restore the data files to a clean state automatically.Changed in version 2.1.2.
If you run the repair option and have data in a journal file, the mongod instance refuses to start. In these cases you should start the mongod without the
--repair
option, which allows the mongod to recover data from the journal. This completes more quickly and is more likely to produce valid data files. To continue the repair operation despite the journal files, shut down the mongod cleanly and restart with the--repair
option.The
--repair
option copies data from the source data files into new data files in therepairPath
and then replaces the original data files with the repaired data files.- Before using
-
--repairpath
<path>
¶ Default: A
_tmp_repairDatabase_<num>
directory under thedbPath
.Specifies a working directory that MongoDB will use during the
--repair
operation. When--repair
completes, the--repairpath
directory is empty, anddbPath
contains the repaired files.The
--repairpath
must be within thedbPath
. You can specify a symlink to--repairpath
to use a path on a different file system.Only available for
mongod
instance using the MMAPv1 storage engine.
-
--journal
¶
Enables the durability journal to ensure data files remain valid and recoverable. This option applies only when you specify the
--dbpath
option. The mongod enables journaling by default on 64-bit builds of versions after 2.0.Not available for
mongod
instances that use the in-memory storage engine.
-
--nojournal
¶
Disables Journaling.
mongod
enables journaling by default.Not available for mongod instances that use the in-memory storage engine.
Warning
When running
mongod
on a replica set with the WiredTiger storage engine, if you turn off journaling with the--nojournal
option, you should also set the replica set configuration optionwriteConcernMajorityJournalDefault
tofalse
.Not available for
mongod
instances that use the in-memory storage engine.
-
--journalOptions
<arguments>
¶ Provides functionality for testing. Not for general use, and will affect data file integrity in the case of abnormal system shutdown.
Not available for
mongod
instances that use the in-memory storage engine.
-
--journalCommitInterval
<value>
¶ Default: 100 or 30
Changed in version 3.2.
The maximum amount of time in milliseconds that the mongod process allows between journal operations. Values can range from 1 to 500 milliseconds. Lower values increase the durability of the journal, at the expense of disk performance. The default journal commit interval is 100 milliseconds.
On MMAPv1, if the journal is on a different block device (e.g. physical volume, RAID device, or LVM volume) than the data files, the default journal commit interval is 30 milliseconds. Additionally, on MMAPv1, when a write operation with
j:true
is pending, mongod will reducecommitIntervalMs
to a third of the set value.On WiredTiger, the default journal commit interval is 100 milliseconds. Additionally, a write with
j:true
will cause an immediate sync of the journal.Not available for
mongod
instances that use the in-memory storage engine.
WiredTiger Options¶
-
--wiredTigerCacheSizeGB
float
¶ New in version 3.0.
Defines the maximum size of the internal cache that WiredTiger will use for all data.
With WiredTiger, MongoDB utilizes both the WiredTiger internal cache and the filesystem cache.
Changed in version 3.2: Starting in MongoDB 3.2, the WiredTiger internal cache, by default, will use the larger of either:
- 60% of RAM minus 1 GB, or
- 1 GB.
For systems with up to 10 GB of RAM, the new default setting is less than or equal to the 3.0 default setting (For MongoDB 3.0, the WiredTiger internal cache uses either 1 GB or half of the installed physical RAM, whichever is larger).
For systems with more than 10 GB of RAM, the new default setting is greater than the 3.0 setting.
Via the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes. Data in the filesystem cache is compressed.
Avoid increasing the WiredTiger internal cache size above its default value.
Note
The
--wiredTigerCacheSizeGB
limits the size of the WiredTiger internal cache. The operating system will use the available free memory for filesystem cache, which allows the compressed MongoDB data files to stay in memory. In addition, the operating system will use any free RAM to buffer file system blocks and file system cache.To accommodate the additional consumers of RAM, you may have to decrease WiredTiger internal cache size.
The default WiredTiger internal cache size value assumes that there is a single
mongod
instance per machine. If a single machine contains multiple MongoDB instances, then you should decrease the setting to accommodate the othermongod
instances.If you run
mongod
in a container (e.g.lxc
,cgroups
, Docker, etc.) that does not have access to all of the RAM available in a system, you must set--wiredTigerCacheSizeGB
to a value less than the amount of RAM available in the container. The exact amount depends on the other processes running in the container.
-
--wiredTigerJournalCompressor
<compressor>
¶ Default: snappy
New in version 3.0.0.
Specifies the type of compression to use to compress WiredTiger journal data.
Available compressors are:
-
--wiredTigerDirectoryForIndexes
¶
New in version 3.0.0.
When you start mongod with
--wiredTigerDirectoryForIndexes
, mongod stores indexes and collections in separate subdirectories under the data (i.e.--dbpath
) directory. Specifically, mongod stores the indexes in a subdirectory namedindex
and the collection data in a subdirectory namedcollection
.By using a symbolic link, you can specify a different location for the indexes. Specifically, when
mongod
instance is not running, move theindex
subdirectory to the destination and create a symbolic link namedindex
under the data directory to the new destination.
-
--wiredTigerCollectionBlockCompressor
<compressor>
¶ Default: snappy
New in version 3.0.0.
Specifies the default type of compression to use to compress collection data. You can override this on a per-collection basis when creating collections.
Available compressors are:
--wiredTigerCollectionBlockCompressor
affects all collections created. If you change the value of--wiredTigerCollectionBlockCompressor
on an existing MongoDB deployment, all new collections will use the specified compressor. Existing collections will continue to use the compressor specified when they were created, or the default compressor at that time.
-
--wiredTigerIndexPrefixCompression
<boolean>
¶ Default: true
New in version 3.0.0.
Enables or disables prefix compression for index data.
Specify
true
for--wiredTigerIndexPrefixCompression
to enable prefix compression for index data, orfalse
to disable prefix compression for index data.The
--wiredTigerIndexPrefixCompression
setting affects all indexes created. If you change the value of--wiredTigerIndexPrefixCompression
on an existing MongoDB deployment, all new indexes will use prefix compression. Existing indexes are not affected.
Replication Options¶
-
--replSet
<setname>
¶ Configures replication. Specify a replica set name as an argument to this set. All hosts in the replica set must have the same set name.
If your application connects to more than one replica set, each set should have a distinct name. Some drivers group replica set connections by replica set name.
-
--oplogSize
<value>
¶ Specifies a maximum size in megabytes for the replication operation log (i.e., the oplog). The mongod process creates an oplog based on the maximum amount of space available. For 64-bit systems, the oplog is typically 5% of available disk space. Once the mongod has created the oplog for the first time, changing the
--oplogSize
option will not affect the size of the oplog.See Oplog Size for more information.
-
--replIndexPrefetch
¶
Default: all
Storage Engine Specific Feature
--replIndexPrefetch
is only available with themmapv1
storage engine.Determines which indexes secondary members of a replica set load into memory before applying operations from the oplog. By default secondaries load all indexes related to an operation into memory before applying operations from the oplog.
Set this option to one of the following:
Value Description none
Secondaries do not load indexes into memory. all
Secondaries load all indexes related to an operation. _id_only
Secondaries load no additional indexes into memory beyond the already existing _id
index.
-
--enableMajorityReadConcern
¶
New in version 3.2.
Enables read concern level of
"majority"
. By default,"majority"
level is not enabled.
Master-Slave Replication¶
These options provide access to conventional master-slave database replication. While this functionality remains accessible in MongoDB, replica sets are the preferred configuration for database replication.
Deprecated since version 3.2: MongoDB 3.2 deprecates the use of master-slave replication for components of sharded clusters.
-
--source
<host><:port>
¶ For use with the
--slave
option, the--source
option designates the server that this instance will replicate.
-
--only
<arg>
¶ For use with the
--slave
option, the--only
option specifies only a single database to replicate.
-
--slavedelay
<value>
¶ For use with the
--slave
option, the--slavedelay
option configures a “delay” in seconds, for this slave to wait to apply operations from the master node.
-
--autoresync
¶
For use with the
--slave
option. When set, the--autoresync
option allows this slave to automatically resync if it is more than 10 seconds behind the master. This setting may be problematic if the--oplogSize
specifies a too small oplog.If the oplog is not large enough to store the difference in changes between the master’s current state and the state of the slave, this instance will forcibly resync itself unnecessarily. If you don’t specify
--autoresync
, the slave will not attempt an automatic resync more than once in a ten minute period.
-
--fastsync
¶
In the context of replica set replication, set this option if you have seeded this member with an up-to-date copy of the entire
dbPath
of another member of the set. Otherwise the mongod will attempt to perform an initial sync, as though the member were a new member.Warning
If the data is not perfectly synchronized and the mongod starts with
fastsync
, then the secondary or slave will be permanently out of sync with the primary, which may cause significant consistency problems.
Sharded Cluster Options¶
-
--configsvr
¶
Declares that this mongod instance serves as the config database of a sharded cluster. When running with this option, clients (i.e. other cluster components) will not be able to write data to any database other than
config
andadmin
. The default port for a mongod with this option is27019
and the default--dbpath
directory is/data/configdb
, unless specified.If using MMAPv1 Storage Engine,
--configsvr
option also sets--smallfiles
.The
--configsvr
option creates a local oplog.Do not use the
--configsvr
option with--shardsvr
. Config servers cannot be a shard server.Changed in version 3.2: Starting in MongoDB 3.2, config servers for sharded clusters can be deployed as a replica set. The replica set config servers must run the WiredTiger storage engine. MongoDB 3.2 deprecates the use of three mirrored
mongod
instances for config servers.In previous versions,
--configsvr
could not be used in conjunction with--replSet
.Changed in version 3.2.19: Do not use the
--configsvr
option with theskipShardingConfigurationChecks
parameter. That is, if you are temporarily starting themongod
as a standalone for maintenance operations, include the parameterskipShardingConfigurationChecks
and exclude--configsvr
. Once maintenance has completed, remove theskipShardingConfigurationChecks
parameter and restart with--configsvr
.
-
--configsvrMode
<string>
¶ Available in MongoDB 3.2 version only
If set to
sccc
, indicates that the config servers are deployed as three mirroredmongod
instances, even if one or more config servers is also a member of a replica set.configsvrMode
only accepts the valuesccc
.If unset, config servers running as replica sets expect to use the “config server replica set” protocol for writing to config servers, rather than the “mirrored mongod” write protocol.
-
--shardsvr
¶
Required if starting a shard server.
Configures this mongod instance as a shard in a sharded cluster. The default port for these instances is
27018
.Changed in version 3.2.19: Do not use the
--shardsvr
option with theskipShardingConfigurationChecks
parameter. That is, if you are temporarily starting themongod
as a standalone for maintenance operations, include the parameterskipShardingConfigurationChecks
and exclude--shardsvr
. Once maintenance has completed, remove theskipShardingConfigurationChecks
parameter and restart with--shardsvr
.
-
--moveParanoia
¶
If specified, during chunk migration, a shard saves, to the
moveChunk
directory of the--dbpath
, all documents migrated from that shard.MongoDB does not automatically delete the data saved in the
moveChunk
directory.
-
--noMoveParanoia
¶
Changed in version 3.2: Starting in 3.2, MongoDB uses
--noMoveParanoia
as the default.During chunk migration, a shard does not save documents migrated from the shard.
TLS/SSL Options¶
See
Configure mongod and mongos for TLS/SSL for full documentation of MongoDB’s support.
-
--sslOnNormalPorts
¶
Deprecated since version 2.6: Use
--sslMode requireSSL
instead.Enables TLS/SSL for mongod.
With
--sslOnNormalPorts
, a mongod requires TLS/SSL encryption for all connections on the default MongoDB port, or the port specified by--port
. By default,--sslOnNormalPorts
is disabled.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslMode
<mode>
¶ New in version 2.6.
Enables TLS/SSL or mixed TLS/SSL used for all network connections. The argument to the
--sslMode
option can be one of the following:Value Description disabled
The server does not use TLS/SSL. allowSSL
Connections between servers do not use TLS/SSL. For incoming connections, the server accepts both TLS/SSL and non-TLS/non-SSL. preferSSL
Connections between servers use TLS/SSL. For incoming connections, the server accepts both TLS/SSL and non-TLS/non-SSL. requireSSL
The server uses and accepts only TLS/SSL encrypted connections. If using x.509 authentication,
--sslCAFile
orssl.CAFile
must be specified.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslPEMKeyFile
<filename>
¶ Specifies the
.pem
file that contains both the TLS/SSL certificate and key. Specify the file name of the.pem
file using relative or absolute paths.You must specify
--sslPEMKeyFile
when TLS/SSL is enabled.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslPEMKeyPassword
<value>
¶ Specifies the password to de-crypt the certificate-key file (i.e.
--sslPEMKeyFile
). Use the--sslPEMKeyPassword
option only if the certificate-key file is encrypted. In all cases, the mongod will redact the password from all logging and reporting output.Changed in version 2.6: If the private key in the PEM file is encrypted and you do not specify the
--sslPEMKeyPassword
option, the mongod will prompt for a passphrase. See TLS/SSL Certificate Passphrase.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--clusterAuthMode
<option>
¶ Default: keyFile
New in version 2.6.
The authentication mode used for cluster authentication. If you use internal x.509 authentication, specify so here. This option can have one of the following values:
Value Description keyFile
Use a keyfile for authentication. Accept only keyfiles. sendKeyFile
For rolling upgrade purposes. Send a keyfile for authentication but can accept both keyfiles and x.509 certificates. sendX509
For rolling upgrade purposes. Send the x.509 certificate for authentication but can accept both keyfiles and x.509 certificates. x509
Recommended. Send the x.509 certificate for authentication and accept only x.509 certificates. If using x.509 authentication,
--sslCAFile
orssl.CAFile
must be specified.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslClusterFile
<filename>
¶ New in version 2.6.
Specifies the
.pem
file that contains the x.509 certificate-key file for membership authentication for the cluster or replica set.If
--sslClusterFile
does not specify the.pem
file for internal cluster authentication, the cluster uses the.pem
file specified in the--sslPEMKeyFile
option.If using x.509 authentication,
--sslCAFile
orssl.CAFile
must be specified.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslClusterPassword
<value>
¶ New in version 2.6.
Specifies the password to de-crypt the x.509 certificate-key file specified with
--sslClusterFile
. Use the--sslClusterPassword
option only if the certificate-key file is encrypted. In all cases, the mongod will redact the password from all logging and reporting output.If the x.509 key file is encrypted and you do not specify the
--sslClusterPassword
option, the mongod will prompt for a passphrase. See TLS/SSL Certificate Passphrase.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslCAFile
<filename>
¶ Specifies the
.pem
file that contains the root certificate chain from the Certificate Authority. Specify the file name of the.pem
file using relative or absolute paths.If using x.509 authentication,
--sslCAFile
orssl.CAFile
must be specified.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslCRLFile
<filename>
¶ Specifies the the
.pem
file that contains the Certificate Revocation List. Specify the file name of the.pem
file using relative or absolute paths.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslAllowInvalidCertificates
¶
Bypasses the validation checks for TLS/SSL certificates on other servers in the cluster and allows the use of invalid certificates to connect.
Note
Starting in MongoDB 3.2.21, if you specify
--sslAllowInvalidCertificates
orssl.allowInvalidCertificates: true
when using x.509 authentication, an invalid certificate is only sufficient to establish a TLS/SSL connection but is insufficient for authentication.When using the
--sslAllowInvalidCertificates
setting, MongoDB logs a warning regarding the use of the invalid certificate.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslAllowInvalidHostnames
¶
New in version 3.0.
Disables the validation of the hostnames in TLS/SSL certificates, when connecting to other members of the replica set or sharded cluster for inter-process authentication. This allows mongod to connect to other members if the hostnames in their certificates do not match their configured hostname.
For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslAllowConnectionsWithoutCertificates
¶
Disables the requirement for TLS/SSL certificate validation that
--sslCAFile
enables. With the--sslAllowConnectionsWithoutCertificates
option, the mongod will accept connections when the client does not present a certificate when establishing the connection.If the client presents a certificate and the mongod has
--sslAllowConnectionsWithoutCertificates
enabled, the mongod will validate the certificate using the root certificate chain specified by--sslCAFile
and reject clients with invalid certificates.Use the
--sslAllowConnectionsWithoutCertificates
option if you have a mixed deployment that includes clients that do not or cannot present certificates to the mongod.For more information about TLS/SSL and MongoDB, see Configure mongod and mongos for TLS/SSL and TLS/SSL Configuration for Clients .
-
--sslDisabledProtocols
<protocol(s)>
¶ New in version 3.0.7.
Prevents a MongoDB server running with TLS/SSL from accepting incoming connections that use a specific protocol or protocols.
--sslDisabledProtocols
recognizes the following protocols:TLS1_0
,TLS1_1
, andTLS1_2
. Specifying an unrecognized protocol will prevent the server from starting.To specify multiple protocols, use a comma separated list of protocols.
Members of replica sets and sharded clusters must speak at least one protocol in common.
See also
-
--sslFIPSMode
¶
Directs the mongod to use the FIPS mode of the installed OpenSSL library. Your system must have a FIPS compliant OpenSSL library to use the
--sslFIPSMode
option.Note
FIPS-compatible TLS/SSL is available only in MongoDB Enterprise. See Configure MongoDB for FIPS for more information.
Audit Options¶
-
--auditDestination
¶
Enables auditing and specifies where mongod sends all audit events.
--auditDestination
can have one of the following values:Value Description syslog
Output the audit events to syslog in JSON format. Not available on Windows. Audit messages have a syslog severity level of
info
and a facility level ofuser
.The syslog message limit can result in the truncation of audit messages. The auditing system will neither detect the truncation nor error upon its occurrence.
console
Output the audit events to stdout
in JSON format.file
Output the audit events to the file specified in --auditPath
in the format specified in--auditFormat
.Note
Available only in MongoDB Enterprise.
-
--auditFormat
¶
New in version 2.6.
Specifies the format of the output file for auditing if
--auditDestination
isfile
. The--auditFormat
option can have one of the following values:Value Description JSON
Output the audit events in JSON format to the file specified in --auditPath
.BSON
Output the audit events in BSON binary format to the file specified in --auditPath
.Printing audit events to a file in JSON format degrades server performance more than printing to a file in BSON format.
Note
Available only in MongoDB Enterprise.
-
--auditPath
¶
New in version 2.6.
Specifies the output file for auditing if
--auditDestination
has value offile
. The--auditPath
option can take either a full path name or a relative path name.Note
Available only in MongoDB Enterprise.
-
--auditFilter
¶
New in version 2.6.
Specifies the filter to limit the types of operations the audit system records. The option takes a string representation of a query document of the form:
The
<field>
can be any field in the audit message, including fields returned in the param document. The<expression>
is a query condition expression.To specify an audit filter, enclose the filter document in single quotes to pass the document as a string.
To specify the audit filter in a configuration file, you must use the YAML format of the configuration file.
Note
Available only in MongoDB Enterprise.
SNMP Options¶
Note
Changed in version 3.2.14: MongoDB Enterprise on macOS does not include support for SNMP due to SERVER-29352.
-
--snmp-subagent
¶
Runs SNMP as a subagent. For more information, see Monitor MongoDB With SNMP on Linux.
-
--snmp-master
¶
Runs SNMP as a master. For more information, see Monitor MongoDB With SNMP on Linux.
inMemory Options¶
-
--inMemorySizeGB
<number>
¶ Default: 50% of physical RAM less 1 GB
New in version 3.2.
Maximum amount of memory to allocate for in-memory storage engine data, including indexes, oplog if the
mongod
is part of replica set, replica set or sharded cluster metadata, etc.By default, the in-memory storage engine uses 50% of physical RAM minus 1 GB.
Enterprise Feature
Available in MongoDB Enterprise only.
Encryption Key Management Options¶
-
--enableEncryption
<boolean>
¶ Default: false
New in version 3.2.
Enables encryption for the WiredTiger storage engine. You must set to
true
to pass in encryption keys and configurations.Enterprise Feature
Available in MongoDB Enterprise only.
-
--encryptionCipherMode
<string>
¶ Default: AES256-CBC
New in version 3.2.
The cipher mode to use for encryption at rest:
Mode Description AES256-CBC
256-bit Advanced Encryption Standard in Cipher Block Chaining Mode AES256-GCM
256-bit Advanced Encryption Standard in Galois/Counter Mode Enterprise Feature
Available in MongoDB Enterprise only.
-
--encryptionKeyFile
<string>
¶ New in version 3.2.
The path to the local keyfile when managing keys via process other than KMIP. Only set when managing keys via process other than KMIP. If data is already encrypted using KMIP, MongoDB will throw an error.
Requires
enableEncryption
to betrue
.Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipKeyIdentifier
<string>
¶ New in version 3.2.
Unique KMIP identifier for an existing key within the KMIP server. Include to use the key associated with the identifier as the system key. You can only use the setting the first time you enable encryption for the
mongod
instance. RequiresenableEncryption
to be true.If unspecified, MongoDB will request that the KMIP server create a new key to utilize as the system key.
If the KMIP server cannot locate a key with the specified identifier or the data is already encrypted with a key, MongoDB will throw an error
Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipRotateMasterKey
<boolean>
¶ Default: false
New in version 3.2.
If true, rotate the master key and re-encrypt the internal keystore.
Enterprise Feature
Available in MongoDB Enterprise only.
See also
-
--kmipServerName
<string>
¶ New in version 3.2.
Hostname or IP address of key management solution running a KMIP server. Requires
enableEncryption
to be true.Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipPort
<number>
¶ Default: 5696
New in version 3.2.
Port number the KMIP server is listening on. Requires that a
kmipServerName
be provided. RequiresenableEncryption
to be true.Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipClientCertificateFile
<string>
¶ New in version 3.2.
String containing the path to the client certificate used for authenticating MongoDB to the KMIP server. Requires that a
kmipServerName
be provided.Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipClientCertificatePassword
<string>
¶ New in version 3.2.
The password (if one exists) for the client certificate passed into
kmipClientCertificateFile
. Is used for authenticating MongoDB to the KMIP server. Requires that akmipClientCertificateFile
be provided.Enterprise Feature
Available in MongoDB Enterprise only.
-
--kmipServerCAFile
<string>
¶ New in version 3.2.
Path to CA File. Used for validating secure client connection to KMIP server.