DAI tmp folder:
    • Used to store all experiment artifacts - experiments, scorers, MLI. 
    • master.db - Database that tracks users to datasets, experiments, MLIBest practices for DAI tmp folder
    • It is always good to take routine backups of the tmp folder after stopping DAI - This will allow recovery in case data is corrupted for some reason.
    • No files should be added or deleted in tmp folder outside of what DAI adds automatically. Doing so can corrupt the data. 
    • Tmp folders should never be mixed across different versions if you already have experiments running on the 2 versions - i.e. legacy tmp folder from DAI 1.8.0 which has old experiments should not be copied over to an existing tmp folder from 1.8.5 which has experiments run on 1.8.5. Doing so will cause master.db to be overwritten and users will lose all new experiments done on 1.8.5
    • Master.db should not be opened by any other application (editors, database readers) - This can corrupt the database and lead to DAI failures.
    • Tmp folders should not be linked across version (ln -s …). All tmp folders should be unique to DAI instances. 
    • Data migration steps from old DAI version to new version:
        ○ Data migration can only take places from an older release to a newer release provided the two releases are compatible. Please reach out to H2O support (support@h2o.ai) for questions related to this
            § Data migration from a newer release to an older release is not possible. 
        ○ Make a backup of the old tmp folder
        ○ Install the latest DAI 
        ○ Copy (not move) old tmp folder to new install tmp folder path
        ○ Start DAI on new install. Please consult H2O support (support@h2o.ai) if you have any questions related to the tmp folder.