When the destination directory cannot store the complete backup ipa-backup fails but does not explain why. This commit adds error-checking to db2ldif(), db2bak() and finalize_backup() and enhances the error message. Fixes: https://pagure.io/freeipa/issue/7647 Signed-off-by: François Cami <fcami@redhat.com> Reviewed-By: Florence Blanc-Renaud <flo@redhat.com> Reviewed-By: Tibor Dudlák <tdudlak@redhat.com> Reviewed-By: Christian Heimes <cheimes@redhat.com> Reviewed-By: Thomas Woerner <twoerner@redhat.com>