Plesk backup finished with warning: Failed to close volume: (5) Input/output error

Symptoms

• Plesk backup at Tools & Settings > Backup Manager finished with the following warning:

  Warning: Extension "Grafana"
  Unable to back up extension package. Error: Failed to create archive: Failed to close volume: (5) Input/output error

• The backup directory is located on an Amazon S3 storage mounted as a drive:

  # df -h
  Filesystem Size Used Avail Use% Mounted on
  ...
  s3fs 256T 0 256T 0% /var/lib/psa/dumps

Cause

Amazon S3 storage is not using a POSIX-compliant file system, that is why it is not recommended to mount it as a backup storage drive.

Resolution

Consider the following alternatives:

1. Use Amazon S3 Backup extension for storing backups in remote S3 storage.
2. Mount storage with a POSIX-compliant filesystem such as Amazon EFS.