You can do this in 2 ways:-
Backup
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1. db2look -d $database -z $schema -e > schema.ddl
2. Export all of the tables to .del files
Restore
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1. db2 -tvf schema.ddl
2. Load nonrecoverable all of the .del files saved in step 2 above
or
1. Put all of the tables associated with the schema in to their own tablespace and use standard online tablespace backup and restores.
Method 2 is a lot quicker to restore the data to a previous state.