If one search’s (magnifying glass icon top right) the OS3 My Cloud section they’ll find several past discussions on attempts to use other operating systems other than OS3 on the single bay My Cloud units. Some with varying degrees of success. See the following big thread:
Clean OS (Debian), OpenMediaVault and other “firmwares”
https://community.wd.com/t/clean-os-debian-openmediavault-and-other-firmwares/93714/
If one has a second gen single bay My Cloud they can update to OS5. For first gen single bay My Cloud’s one is stuck either with the OS3 v.4 firmware, rolling their own firmware from the WD GPL file(s) for the single bay, or trying alternate firmware mentioned in the above link or in other posts. The main problem with the My Cloud enclosure and its motherboard/backplane is the limited hardware (processor and RAM) that it uses. It will be a limiting factor when attempting to use third party NAS operating systems like OMV or Debain. One may find certain features of alternate OS’s may not work or will require additional coding to get working.
Another option, if the hard drive isn’t dead or going bad is to pull the hard drive from it’s enclosure and use an old desktop (or similar) computer and create your own NAS using free NAS software. Plenty of DIY guides out there on rolling your own NAS using a number of open source or free NAS operating systems.
As always one proceeds at their own risk when modifying the firmware. Modifying the firmware requires much extra skill and knowledge that one will have to search for and learn.
Otherwise just follow one of the unbrick methods for the OS3 single bay My Cloud units to restore the OS3 firmware to it. Generally it is best to perform the unbrick process for a first gen single bay My Cloud hard drive using Linux or a Linux boot disk. One could even use a 2.5 inch HDD if they wanted too in a first gen single bay My Cloud.
