copyfs software package provides Versioning filesystem for FUSE, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install copyfs
copyfs is installed in your system.
Make ensure the copyfs package were installed using the commands given below,
$ sudo dpkg-query -l | grep copyfs *
You will get with copyfs package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Utilities |
| Package | copyfs |
| Version | 1.0.1-5 |
| Description | Versioning filesystem for FUSE |
| Sub Section | Utils |