Error "manifest blob unknown" "blob unknown to registry" while pushing images to registry in OpenShift 4

Issue

• While pushing images to the OpenShift 4 registry, the error below appears randomly:

  Error: Error copying image to the remote destination: Error writing manifest: Error uploading manifest 7.5.2 to image-registry/hostname/repository: errors:
  manifest blob unknown: blob unknown to registry
  manifest blob unknown: blob unknown to registry
  

• Error writing manifest in OpenShift 4 registry:

  Error uploading manifest latest to `image-registry/hostname/repository` : manifest blob unknown: blob unknown to registry
  

• NFS is used as a storage backend for RHOCP internal registry.