# Mongod configuration

**URL:** https://forums.percona.com/t/mongod-configuration/29286
**Category:** Percona Operator for MongoDB
**Created:** [March 21, 2024, 4:05pm UTC](https://forums.percona.com/t/mongod-configuration/29286 "2024-03-21T16:05:29Z")
**Posts on this page:** 1
**Showing post:** 2

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### Author: ![Sergey\_Pronin](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/sergey_pronin/32/14887_2.png) [@Sergey\_Pronin](https://forums.percona.com/u/Sergey_Pronin)
#### Post date: [March 21, 2024, 7:57pm UTC](https://forums.percona.com/t/mongod-configuration/29286/2 "2024-03-21T19:57:42Z")

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Hello @Sergey_Zelenov1 ,

as you can see there is this flag:

```auto
        - --config=/etc/mongodb-config/mongod.conf

```

This is where the configuration is stored.  
If you exec into the container, you would see the file has these parameters and they are actually applied.

This is in my container:

```auto
$ cat /etc/mongodb-config/mongod.conf 
systemLog:
  quiet: true
replication:
  oplogSizeMB: 500

```

As for rs.printReplicationInfo() and the size not changing, have you tried to run replSetResizeOplog? As per mongodb docs:

> Once the [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod/#mongodb-binary-bin.mongod) has created the oplog for the first time, changing the [`replication.oplogSizeMB`](https://www.mongodb.com/docs/manual/reference/configuration-options/#mongodb-setting-replication.oplogSizeMB) option will not affect the size of the oplog. To change the maximum oplog size after starting the [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod/#mongodb-binary-bin.mongod), use [`replSetResizeOplog`](https://www.mongodb.com/docs/manual/reference/command/replSetResizeOplog/#mongodb-dbcommand-dbcmd.replSetResizeOplog). [`replSetResizeOplog`](https://www.mongodb.com/docs/manual/reference/command/replSetResizeOplog/#mongodb-dbcommand-dbcmd.replSetResizeOplog) enables you to resize the oplog dynamically without restarting the [`mongod`](https://www.mongodb.com/docs/manual/reference/program/mongod/#mongodb-binary-bin.mongod) process. To persist the changes made using [`replSetResizeOplog`](https://www.mongodb.com/docs/manual/reference/command/replSetResizeOplog/#mongodb-dbcommand-dbcmd.replSetResizeOplog) through a restart, update the value of [`oplogSizeMB`.](https://www.mongodb.com/docs/manual/reference/configuration-options/#mongodb-setting-replication.oplogSizeMB)

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