• skip_access_check — if true, it’s possible to use read only credentials with regular MergeTree table. But you would need to disable merges (prefer_not_to_merge setting) on s3 volume as well.

  • send_metadata — if true, ClickHouse will populate s3 object with initial part & file path, which allow you to recover metadata from s3 and make debug easier.

Restore metadata from S3



  1. ClickHouse need RW access to this bucket

In order to restore metadata, you would need to create restore file in metadata_path/_s3_disk_name_ directory:

touch /var/lib/clickhouse/disks/_s3_disk_name_/restore

In that case ClickHouse would restore to the same bucket and path and update only metadata files in s3 bucket.



  1. ClickHouse needs RO access to the old bucket and RW to the new.
  2. ClickHouse will copy objects in case of restoring to a different bucket or path.

If you would like to change bucket or path, you need to populate restore file with settings in key=value format:

cat /var/lib/clickhouse/disks/_s3_disk_name_/restore

Last modified 2023.01.25: fix links (6332723)