File Based Configuration

In addition to accepting Command Line Parameters, MongoDB can also be configured using a configuration file. A configuration file to use can be specified using the -f or --config command line options. On some packaged installs of MongoDB (for example Ubuntu & Debian) the default file can be found in /etc/mongodb.conf which is automatically used when starting and stopping MongoDB from the service.

The following example configuration file demonstrates the syntax to use:

# This is an example config file for MongoDB.
dbpath = /var/lib/mongodb
bind_ip = 127.0.0.1
noauth = true # use 'true' for options that don't take an argument
verbose = true # to disable, comment out.

Parameters

Before 2.0
Unfortunately flag parameters like "quiet" will register as true no matter what value you put after them. So don't write this: "quiet=false", just comment it out, or remove the line.

In 2.0, you can use option=false in the config file and it will be handled correctly (the option will be ignored).

Suppose you were running 1.8 and using a config file with the contents:

auth = false

This would actually enable authentication in 1.8. If you upgrade to 2.0, this would suddenly be parsed correctly, turning off authentication (which you might not want, if you've been running with it on forever). Thus, if you start up with 2.0+ and you have any option=false options in your config file, you'll get a warning that looks like:

warning: remove or comment out this line by starting it with '#', skipping now : auth=false

This is to let you know that this option is being skipped. If you want this option skipped, feel free to ignore this warning.

Basic database configuration

Parameter	Meaning	Example
dbpath	Location of the database files	`dbpath = /var/lib/mongodb`
port	Port the mongod will listen on	`port = 27017`
bind_ip	Specific IP address that mongod will listen on	`bind_ip = 127.0.0.1`
logpath	Full filename path to where log messages will be written	`logpath = /var/log/mongodb/mongodb.log`
logappend	Whether the log file will be appended to or over-written (default) at start-up	`logappend = true`

Logging

Parameter	Meaning	Example
cpu	Enable periodic logging of CPU utilization and I/O wait	`cpu = true`
verbose	Verbose logging output (same as `v = true`)	`verbose=true`
v[vvvv]	Level of verbose logging output	`vvvvv = true`

Security

Parameter	Meaning	Example
noauth	Turn authorization on/off. Off is currently the default	`noauth = true`
auth	Turn authorization on/off. Off is currently the default	`auth = true`
keyFile	Private key for cluster authentication.	`keyFile = /var/lib/mongodb/key`

Administration & Monitoring

Parameter	Meaning	Example
nohttpinterface	Disable the HTTP interface. The default port is 1000 more than the dbport	`nohttpinterface = true`
rest	Turn on simple rest API	`rest = true`
noscripting	Turns off server-side scripting. This will result in greatly limited functionality	`noscripting = true`
notablescan	Turns off table scans. Any query that would do a table scan fails.	`notablescan = true`
noprealloc	Disable data file preallocation.	`noprealloc = true`
nssize	Specify .ns file size for new databases in MB	`nssize = 16`
mms-token	Account token for Mongo monitoring server.	`mms-token = mytoken`
mms-name	Server name for Mongo monitoring server.	`mms-name = monitor.example.com`
mms-interval	Ping interval for Mongo monitoring server in seconds.	`mms-interval = 15`
quota	Enable quota management	`quota = true`
quotaFiles	Determines the number of files per Database (default is 8)	`quotaFiles = 16`

Replication

Parameter	Meaning	Example
opIdMem	Size limit for in-memory storage of op ids in bytes	`opIdMem = 1000`
oplogSize	Custom size for replication operation log in MB.	`oplogSize = 100`

Master-slave Replication

Parameter	Meaning	Example
master	In replicated mongo databases, specify here whether this is a slave or master	`master = true`
slave	In replicated mongo databases, specify here whether this is a slave or master	`slave = true`
source	Specify the	`source = master.example.com`
only	Slave only: specify a single database to replicate	`only = master.example.com`
autoresync	Automatically resync if slave data is stale	autoresync
fastsync	Indicate that this instance is starting from a dbpath snapshot of the repl peer

Replica Sets

Parameter	Meaning	Example
replSet	Use replica sets with the specified logical set name. Typically the optional seed host list need not be specified.	`replSet = <setname>[/<seedlist>]`

Sharding

Parameter	Meaning	Example
shardsvr	Indicates that this mongod will participate in sharding *Optional and just changes the default port	`shardsvr = true`

Journaling

Parameter	Meaning	Example
journal	Whether writes will be journaled or not. This feature enables fast recovery from crashes	`journal = true`
nojournal	Turns off journaling if it is enabled by default (1.9.2+)	`nojournal = true`

Notes

Lines starting with octothorpes (#) are comments
Options are case sensitive
The syntax is assignment of a value to an option name
All command line options are accepted, for example "vvvv=true"