> # Guidelines and Limitations

> This section explains the database guidelines for this feature.

> A database merge refers to a union of the configuration database and static (unlearned) entries in the active DPVM database. For information about CFS merge support, refer to the Cisco MDS 9000 Family NX-OS System Management Configuration Guide for detailed concepts.

> When merging the DPVM database between two fabrics, follow these guidelines:

> - Verify that the activation status and the autolearn status is the same is both fabrics.
> - Verify that the combined number of device entries in each database does not exceed 16 K.

> Caution | If you do not follow these two conditions, the merge will fail. The next distribution will forcefully synchronize the databases and the activation states in the fabric.

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