WD appears to claim one cannot officially downgrade back to OS3 (buried in this OS5 announcement link). Unofficially, like so many things on the My Cloud, it appears one can do so. One person in the OS3 single bay My Cloud subforum indicates they were able to roll back to OS3 but didnt’ give detailed instructions of how to do so. Other examples for multi bay units below.
With out knowing exactly what My Cloud model you are using it is unknown how one would roll back such a model easily; or if it is possible at all which is something I did indicate in prior posts. More on how to possibly roll back multi bay models below. On the second gen single bay My Cloud models, because the firmware is stored on the hard drive it can be replaced with an earlier version through various different “unbrick” methods. Obviously one would have to backup their user data before performing such a drastic measure. Depending on what method is used one may be repartitioning and reformatting the various partitions used by the firmware including the user data partition.
User Fox_exe has a set of directions for installing OS3 firmware to the second gen single bay My Cloud hard drive that can be done using Telnet and a USB flash drive:
User Fox_exe repositories:
Main Repository: https://fox-exe.ru/WDMyCloud/
Second Gen: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/
Second gen directions:
English: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/_Unbricking_en.txt
Russian: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/_Unbricking_ru.txt
usbrecovery.tar.gz: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/usbrecovery.tar.gz
Alternate method files:
uImage-wdrecovery: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/Developing/uImage-wdrecovery
uRamdisk-wdrecovery: https://fox-exe.ru/WDMyCloud/WDMyCloud-Gen2/Developing/uRamdisk-wdrecovery
Latest second gen firmware: http://support.wdc.com/downloads.aspx?g=904
It is possible one may be able to skip the portion of those directions that recreate the various partitions and use just the portion of the directions on pushing the two files (uImage-wdrecovery and uRamdisk-wdrecovery) to their respective locations detailed in those directions. Boot the second gen single bay unit into safe mode, then install the downloaded OS3 firmware to the unit.
For multi bay My Cloud models one may have to search through the OS5 subforum for that model, or possibly that model’s OS3 subforum, to see if there is a specific method or set of directions on how to reinstall the OS3 firmware on that model. Some other threads for other OS5 multi bay units where people have, apparently, been able to roll back to OS3.
For the non technically inclined, rolling back the firmware may involve the user having some knowledge of; Linux, Linux commands, SSH, Telnet or other technical methods and commands. If one is unfamiliar with how to do something outlined in the various links above, they may have to do some learning and internet searching to understand what they are doing.
As always proceed at your own risk and backup data before hand!
