CBFS Storage is capable of storing a single vault across multiple files on disk; this is known as a multipart vault. To create a multipart vault, set the PartSize configuration setting to a non-zero value before the vault is created. CBFS Storage will automatically create, resize, and delete individual part files as necessary over time (please refer to the Vault Size topic for more information).
Multipart vaults are typically used by applications which operate in environments with file size constraints. For example, if an application needed to store a 16GB vault on a FAT32 filesystem, it could use a multipart vault with a 4GB part size.
Existing vaults cannot be converted between multipart and non-multipart, and a multipart vault's size cannot be changed after creation. Also, multipart vaults are not supported in Callback Mode (since it already gives applications full control over how/where a vault is stored); the PartSize configuration setting is simply ignored.