Unable to create remote backup, the local backup will be created: Part number must be an integer between 1 and 1000, inclusive

Symptoms

• The following error is shown in Tools & Settings > Backup Manager:
  

  CONFIG_TEXT: Unable to create a remote backup, the local backup will be created. Error: Unable to export backup: Transport error: Extension transport: ext://s3-backup/server/: Part number must be an integer between 1 and 1000, inclusive

• OVHcloud OpenStack-based S3-compatible storage is configured as a custom S3 storage in Plesk in Tools & Settings > Backup Manager > Remote Storage Settings > Amazon S3 Backup.

Cause

Amazon S3 Backup Extension bug with ID EXTPLESK-1846, which will be fixed in a future update.

Resolution

As a workaround, divide backup into smaller parts:

1. Log into Plesk;
2. Navigate to Tools & Settings > Backup Manager > Scheduled Backup Settings > Backup settings section;
3. Set the value Create a multivolume backup, volume size (MB) as 20000 Mb.