File Assets in dotCMS live in both the database and the filesystem. The metadata for an asset lives in the database while the the hard assets (binary images, text, css, etc...) live on the file system. The these files live under the directory /dotCMS/assets. File Assets are saved based on their inodes. The inode is then saved in a b-tree format under /dotCMS/assets. So a PDF with an inode of 71b8a1ca-37b6-4b6e-a43b-c7482f28db6c would live under /dotCMS/assets/7/1/71b8a1ca-37b6-4b6e-a43b-c7482f28db6c.pdf
The location of the assets is configurable in the dotmarketing-config.properties file - Overwrite in a plugin using the dotmarketing-config-ext.properties in the /plugins/com.dotcms.config/conf folder.
ASSET_PATH = /assets