MongoDB – Backup and Restoration

Data backup is one of the most highly required processes for any database management system as data can be lost or get corrupted to overcome these drawbacks we need database backup. Database backup is a copy of a database that already exists. In MongoDB, mongodump tool is used to take the data backup. And mongorestore tool is used to restore the backup data. 

Data Backup

In MongoDB, mongodump tool is used to take the data backup. It simply dumps all the data stored into a dump directory of MongoDB. Backed-up data is in BSON format also known as BSON data dumps. By default, the backup is stored in mongodb’s bin\dump folder to specify a different output directory we can use the –out option. Mongodump is used in two ways with or without argument.

Without Argument:

Without any arguments, mongodump connects with MongoDB instance on the local system on port 27017 and creates a backup of every database and every collection. 

mongodump

With Argument: 

By specifying the database in the argument by which we can limit the amount of data stored in the database dump

mongodump --db databaseName --collection collectionName

To specify a different output directory we can use the –out option:

mongodump –db databaseName –collection collectionName –out c:\backup

Example 1: Backing up all the databases

Here we have 10 databases which all get backed up in the folder backupDatabase.

Note– exit mongo shell by ctrl+c to use the mongodump command.

mongodump --out c:\backupDatabase

Example 2: Backing up the specified collection

Here, we are making a backup of the collection student which contains 6 documents and is inside the GeeksForGeeks database, the backup is made inside the GFGbackup Folder.

mongodump –db GeeksForGeeks –collection students –out c:\GFGbackup 

Data Restoration

In MongoDB, mongorestore utility is used to restore the backup data. It restores the binary backup created by mongodump utility(i.e., BSON data dumps). It can restore either an entire database backup or a subset of the backup. It also restores the indexes which are created for any collection inside that database. By default, mongorestore looks for a database backup in mongodb’s bin\dump folder which is also the default folder for mongodump command for dumping the backup.

To restore all the database use –

mongorestore dump

To restore a specific collection use-

mongorestore  –db databaseName –collection collectionName directory\collectionName.bson

Example:

In this example, we are using a database GeeksForGeeks which has 4 collections. We are firstly going to make a backup of student collection and then drop the student collection and then restore the student collection.

To make backup we use –

mongodump --db GeeksForGeeks --collection students --out c:\GFGbackup 

The backup will be stored in c:\GFGbackup folder

Now we will drop students collection by using-

db.students.drop() 

Now we will restore student collection by using –

mongorestore –db GeeksForGeeks –collection students c:\GFGbackup\GeeksForGeeks\students.bson