How to backup and restore data

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

Snapshots are created periodically based on the value defined with the --storage-snapshot-interval-sec configuration flag in the configuration file. If you need help adjusting the configuration, check out the how-to guide on changing the configuration.

Create backup

To create a backup, follow the steps below:

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;

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 the data directory and unlock it

Copy the data directory or a single WAL or snapshot file to a backup location.

Copy files if you are using Memgraph on Linux

If you are using Linux to run Memgraph, here are the steps for copying files:

1. Start your Memgraph instance.

2. Open a new Linux terminal and check the location of the permanent data directory:

grep -A 1 'permanent data' /etc/memgraph/memgraph.conf

If you are getting a permission error, execute the sudo su command to get access privileges and then try to change the working directory again.

Your output should look something like this:

# Path to directory in which to save all permanent data. [string]
--data-directory=/var/lib/memgraph

As you can see, the path is the default one: /var/lib/memgraph.

3. Locate the files that you want to backup. Let's say that you want to copy the latest snapshot, list the content of the snapshot directory and then copy the latest file.

ls -l /var/lib/memgraph/snapshots/

total 35920
-rw-r----- 1 memgraph memgraph  7185673 Mar 25 13:52 20220325125206991975_timestamp_2622
-rw-r----- 1 memgraph memgraph 12521724 Mar 25 13:52 20220325125237040637_timestamp_3028
-rw-r----- 1 memgraph memgraph 17064381 Mar 25 13:53 20220325125308366007_timestamp_3380

4. Copy a file from the snapshot directory to the backup folder:

cp /var/lib/memgraph/snapshots/20220325125308366007_timestamp_3380 ~/backup/

If you need help copying the files from the Docker container, check out the Working with docker guide.

Then, 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. Lock the data directory

To disable changes in the data directory, run the following query in mgconsole or Memgraph Lab:

LOCK DATA DIRECTORY;

2. Copy the snapshot into the data directory

Copy the data directory or, empty the directory, then copy a single WAL or snapshot file into it.

If you need help copying the files from the Docker container, check out the Working with docker guide.

3. Unlock the directory

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

UNLOCK DATA DIRECTORY;

Memgraph should restore the data from the files in the data directory.