The My Cloud EX2 Ultra is different than the single bay/single drive My Cloud device, which is the general subject of this subforum. For specific questions about the EX2 Ultra, see the dedicated subforum for the EX2 series of devices. One can use the forum search feature (magnifying glass icon upper right) to search through that subforum.
Generally COPS (https://blog.slucas.fr/projects/calibre-opds-php-server/) is what one would use to manage ebooks on a Linux OS device. However because of the custom nature of the Linux firmware on these My Cloud devices running non WD supported 3rd party apps can be difficult/tricky or impossible.
There is some discussion about installing COPS on the PR2100 series of My Cloud devices that may be of interest. Maybe one can adapt that method to work on an EX2 Ultra.
