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Back up & restore database

This section outlines how to perform database backups for your beacon node and validator client. The validator client services expose an HTTP backup endpoint which is the safest way to trigger a database backup.

Doing manual folder backups while the cllient is running is not safe

If you perform backups by manually copying the database while the client is running, you risk copying a corrupted database! You might be copying the folder right when the client is in the middle of writing data to the database, and could end up with a bad backup.

Beacon node​

Backing up the database manually​

Your first need to find your base directory. If you don't usually run your beacon node with the --datadir option, then you can find the base directory by running your beacon node with the --help option. It will vary depending the operating system you use.

For MacOS, it is:

--datadir value      Data directory for the databases. (default: "/Users/<user>/Library/Eth2")

If you usually run your beacon node with the --datadir option, then your base directory is the one specified by the --datadir option.

Finally, your database is located in the beaconchaindata subdirectory, at the beaconchain.db file.

Restoring from a backup​

Ensure your beacon node is turned off if restoring a backup. You can restore a beacon chain DB from a backup file with the following command:

Using the Prysm installation script

prysm.sh beacon-chain db restore --restore-source-file=/path/to/backup --restore-target-dir=/path/to/desired/datadir

Using Bazel

bazel run //cmd/beacon-chain -- db restore --restore-source-file=/path/to/backup --restore-target-dir=/path/to/desired/datadir

Validator client​

Add the backup webhook flags to your validator client​

Add the following flags to your validator client:

  • --enable-db-backup-webhook: Serve an http server to initiate database backups. The handler is served on the validator client's monitoring host and port. Default endpoint is http://127.0.0.1:8081/db/backup if the flag is enabled.
  • --db-backup-output-dir: Folder path to where backups will be output to, such as /path/to/mybackups.

Now, your validator client will expose an HTTP endpoint http://monitoringhost:monitoringport/db/backup, which is http://127.0.0.1:8081/db/backup by default. You can hit this endpoint using curl or any other tool you prefer, and a backup will initiate which will be output to your --db-backup-output-dir path.

Restoring from a backup​

Ensure your validator client is turned off if restoring a backup. You can restore a validator DB from a backup file with the following command:

Using the Prysm installation script

prysm.sh validator db restore --restore-source-file=/path/to/backup --restore-target-dir=/path/to/desired/datadir

Using Bazel

bazel run //cmd/validator -- db restore --restore-source-file=/path/to/backup --restore-target-dir=/path/to/desired/datadir