Add docs for migrating to MongoDB from FerretDB

website/docs/migration/_category_.yml

@@ -0,0 +1,7 @@
+---
+label: Migrating to FerretDB
+position: 9
+link:
+  type: generated-index
+  description: >
+    This section details the procedures on how to migrate to FerretDB

website/docs/migration/migrating-to-ferretdb.md

@@ -0,0 +1,66 @@
+---
+sidebar_position: 2
+---
+
+# Migrate from MongoDB to FerretDB
+
+Before you begin this section of the migration process, go through the pre-migration process so as to ensure a successful migration from MongoDB to FerretDB:
+
+- [Pre-migration testing](premigration-testing.md)
+
+This guide will help you migrate your data from MongoDB – locally or online – to FerretDB.
+
+As an open-source MongoDB alternative, FerretDB is built to work with many MongoDB tools.
+In that case, you can migrate your data using MongoDB native tools such as `mongodump`/`mongorestore` and `mongoexport`/`mongoimport`.
+
+Before you go forward with the migration, you need to have the following:
+
+- MongoDB connection URI
+- FerretDB connection URI
+- MongoDB native tools
+
+## Backup your MongoDB data
+
+To backup your MongoDB instance using `mongodump` or `mongoexport`, you'll need to set the connection string to your MongoDB instance (e.g. `"mongodb://127.0.0.1:27017"`) to run the following command:
+
+```sh
+mongodump --uri="mongodb://<yourusername>:<yourpassword>@<host>:<port>"
+```
+
+The `mongodump` command will create a dump of all the data in the instance, consisting of BSON files of all the collections.
+Also, you can migrate a specific database (e.g. `--db=test`) or collection (e.g. `--collection=supply`) using their respective parameters after the `--uri` connection string.
+
+:::caution
+If you include the database in your connection string, there's no need to specify a database name for the backup or restore process.
+:::
+
+```sh
+mongoexport --uri="mongodb://<yourusername>:<yourpassword>@<host>:<port>" --db=<database-name> --collection=<collection-name> --out=<collection>.json
+```
+
+On the other hand, `mongoexport` does not provide a direct way to export all the collections at once, like `mongodump` does.
+
+Instead, you need to set the connection string to connect with your preferred database and then run the command together with the parameters for the collection (`--collection=myCollection`) and the directory you want to export to (e.g. `--out=collection-name.json`).
+
+## Restore your data to FerretDB
+
+To restore or import your backed-up data to FerretDB, set the connection string to your FerretDB instance and use `mongorestore` and `mongoimport`.
+
+Run the following command in your terminal, from your `dump` folder:
+
+```sh
+mongorestore --uri="mongodb://<yourusername>:<yourpassword>@<host>:<port>/?authMechanism=PLAIN"
+```
+
+With this command, you can restore all the data in `dump` into your FerretDB instance.
+You can also specify the database and collection (`dump/<database>/<collection>`) you want to restore from the `dump` folder, according to your preferences.
+
+To import your database using `mongoimport`, run the command from the terminal directory where you exported your data:
+
+````sh
+
+```sh
+mongoimport--uri="mongodb://<yourusername>:<yourpassword>@<host>:<port>/?authMechanism=PLAIN" --db=<database-name> --collection=<collection-name> --file=<collection>.json
+````
+
+The command will import the specified collection you exported from your MongoDB instance to FerretDB.

website/docs/migration.md → website/docs/migration/premigration-testing.md

@@ -1,19 +1,19 @@
 ---
-sidebar_position: 9
+sidebar_position: 1
 ---
 
-# Migrating from MongoDB to FerretDB
+# Pre-migration testing
 
 To ensure a smooth and successful migration from MongoDB, we offer several methods through which you can test your application with FerretDB.
 
 ## Operation modes
 
 We offer multiple operation modes which help facilitate the testing of your application by enabling FerretDB to act as a proxy.
-For more details, refer to the [operation modes](configuration/operation-modes.md).
+For more details, refer to the [operation modes](../configuration/operation-modes.md).
 
 ### Manual and automated testing with `diff-normal` mode
 
-For details on how to install FerretDB, refer to the [quickstart guide](../quickstart-guide/).
+For details on how to install FerretDB, refer to the [quickstart guide](../../quickstart-guide/).
 
 You can manually test your application or use integration tests, among other methods.
 Afterward, you can inspect the differential output for errors or inconsistencies between responses that require your attention.
@@ -22,7 +22,7 @@ As an example, let us say that your application performs some complex query and
 You would do the following:
 
 1. Start FerretDB in `diff-normal` mode.
-   This can be achieved by using the `--mode` [flag](configuration/flags.md) or by setting the `FERRETDB_MODE` environment variable.
+   This can be achieved by using the `--mode` [flag](../configuration/flags.md) or by setting the `FERRETDB_MODE` environment variable.
 2. Run `mongosh` and insert some documents.
 3. Run a query to fetch the first post from each author sorted by date and author.
 
@@ -83,7 +83,7 @@ You would do the following:
 Continuing with the same example above, we can further examine the diff output while in `diff-proxy` mode.
 
 1. Run FerretDB in `diff-proxy` mode.
-   This can again be achieved by using the `--mode` [flag](configuration/flags.md) or by setting the `FERRETDB_MODE` environment variable as already shown.
+   This can again be achieved by using the `--mode` [flag](../configuration/flags.md) or by setting the `FERRETDB_MODE` environment variable as already shown.
 2. Re-run the query.
 
    ```js