ndb_restore — Restore an NDB Cluster Backup ndb_restore  to an earlier version of NDB Cluster. Such tables use  .sdi  files which are not understood by older versions of  mysqld . A backup taken in NDB 8.0.14 or later of tables which were created in NDB 8.0.13 or earlier, and which have not been altered since upgrading to NDB 8.0.14 or later, should be restorable to older versions of NDB Cluster. •The  NDB_STORED_USER  privilege is not supported prior to NDB 8.0.18. •Encrypted backups created in NDB 8.0.22 and later cannot be restored using  ndb_restore  from NDB 8.0.21 or earlier. Since it is possible to restore metadata and table data separately, you can in such cases restore the table schemas from a dump made using  mysqldump , or by executing the necessary  CREATE TABLE statements manually, then import only the table data using  ndb_restore  with the  --restore-data option. •NDB Cluster 8.0.18 and later supports up to 144 data nodes, while earlier versions support a maximum of only 48 data nodes. See Restoring to Fewer Nodes Than the Original, for information with situations in which this incompatibility causes an issue. Restoring an NDB backup to a later version of NDB Cluster In general, it should be possible to restore a backup created using the  ndb_mgm  client  START BACKUP command in an older version of NDB to a newer version, provided that you use the  ndb_restore  binary that comes with the newer version. (It may be possible to use the older version of  ndb_restore , but this is not recommended.) Additional potential issues are listed here: •When restoring the metadata from a backup ( --restore-meta  option),  ndb_restore  normally attempts to reproduce the captured table schema exactly as it was when the backup was taken. Tables created in versions of NDB prior to 8.0.14 use  .frm  files for their metadata. These files can be read by the  mysqld  in NDB 8.0.14 and later, which can use the information contained therein to create the  .sdi  files used by the MySQL data dictionary in later versions. •When restoring an older backup to a newer version of NDB, it may not be possible to take advantage of newer features such as hashmap partitioning, greater number of hashmap buckets, read backup, and different partitioning layouts. For this reason, it may be preferable to restore older schemas using mysqldump  and the  mysql  client, which allows NDB to make use of the new schema features. •Tables using the old temporal types which did not support fractional seconds (used prior to MySQL 5.6.4 and NDB 7.3.31) cannot be restored to NDB 8.0 using  ndb_restore . You can check such tables using  CHECK TABLE , and then upgrade them to the newer temporal column format, if necessary, using REPAIR TABLE  in the  mysql  client; this must be done prior to taking the backup. See Section 2.11.5, “Preparing Your Installation for Upgrade” , for more information. You also also restore such tables using a dump created with  mysqldump . •Distributed grant tables created in NDB 7.6 and earlier are not supported in NDB 8.0. Such tables can be restored to an NDB 8.0 cluster, but they have no effect on access control. 23.4.23.2 Restoring to a different number of data nodes It is possible to restore from an NDB backup to a cluster having a different number of data nodes than the original from which the backup was taken. The following two sections discuss, respectively, the cases where the target cluster has a lesser or greater number of data nodes than the source of the backup. 4394