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Version: 2.9.0

How to backup and restore data

While running, Memgraph generates various files in its data directory, including the durability files, that is, snapshots and WALs that contain Memgraph's data in a recoverable format and are located in the wal and snapshots folders in the data directory. On startup, Memgraph searches for previously saved durability files and uses them to recreate the most recent database state.

When talking about the data directory in the context of backup and restore, we are actually talking about two directories, snapshots and wal, which are usually located in the /var/lib/memgraph directory.

Snapshots are created periodically based on the value defined with the --storage-snapshot-interval-sec configuration flag, as well as upon exit based on the configuration flag --storage-snapshot-on-exit, defined by the configuration file.

You can configure the exact snapshot creation behavior by defining the relevant. If you need help adjusting the configuration, check out the how-to guide on changing the configuration.

Related - Reference Guide

Create backup​

Follow these steps to create database backup:

  1. Create a snapshot

    If necessary, create a snapshot of the current database state by running the following query in mgconsole or Memgraph Lab:

    CREATE SNAPSHOT;

    The snapshot is saved in the snapshots directory of the data directory (/var/lib/memgraph).

  2. Lock the data directory

    Durability files are deleted when an event is triggered, for example, exceeding the maximum number of snapshots.

    To disable this behavior, run the following query in mgconsole or Memgraph Lab:

    LOCK DATA DIRECTORY;

  3. Copy files

    Copy snapshot files (from the snapshots directory) and any additional WAL files (from the wal directory) to a backup location.

    If you've just created a snapshot file there is no need to backup WAL files.

    To help copying the files from the Docker container, check out the Working with docker guide.

  4. Unlock the data directory

    Run the following query in mgconsole or Memgraph Lab to unlock the directory:

    UNLOCK DATA DIRECTORY;

    Memgraph will delete the files which should have been deleted before locking and allow any future deletion of the durability files.

Restore data​

To restore data from a backup

  1. Empty the wal directory

    If you want to restore data only from the snapshot file, ensure that the wal directory is empty:

    • Find the container ID using a docker ps command, then enter the container using:

      docker exec -it CONTAINER_ID bash

    • Position yourself in the /var/lib/memgraph/wal directory and rm *

  2. Stop the instance using docker stop CONTAINER_ID

  3. Start the instance by adding a -v ~/snapshots:/var/lib/memgraph/snapshots flag to the docker run command, where the ~/snapshots represents a path to the location of the directory with the back-up snapshot, for example: 

    docker run -p 7687:7687 -p 7444:7444 -v ~/snapshots:/var/lib/memgraph/snapshots memgraph/memgraph

  4. If you want to copy both WAL and snapshot files start the instance by adding a -v ~/snapshots:/var/lib/memgraph/snapshots -v ~/wal:/var/lib/memgraph/wal flags to the docker run command, where the ~/snapshots represents a path to the location of the backed-up snapshot directory, and ~/wal represents a path to the location of the backed-up wal directory for example: 

    docker run -p 7687:7687 -p 7444:7444 -v ~/snapshots:/var/lib/memgraph/snapshots -v ~/wal:/var/lib/memgraph/wal memgraph/memgraph