If an error code is returned when issuing a backup request, the most likely cause is insufficient memory or disk space. You should check that there is enough memory allocated for the backup.
You should also make sure that there is sufficient space on the hard drive partition of the backup target.
NDB does not support repeatable
reads, which can cause problems with the restoration process.
Although the backup process is “hot”, restoring a
MySQL Cluster from backup is not a 100% “hot”
process. This is due to the fact that, for the duration of the
restore process, running transactions get nonrepeatable reads
from the restored data. This means that the state of the data is
inconsistent while the restore is in progress.