Grid definition does not contain property "gd.tablename". In-memory database will be used to store grid data.
All data will be lost after Jira (or plugin) restarts.
This message indicates that any modifications in the table grid will not be stored in a database. The reason is that the add-on doesn't know in what database / table the content should be stored, which is an important detail to mention.
To get rid of this message you will have to specify a gd.tablename (the name of the table where the data must be stored) and a database using either gd.ds=jira or by specifying the hibernate details for gridds.
Check connecting the grid to a database for more details.