Can I use my old MyCloud (OS3) as a backup drive for new MyCloud Home?

Hi all.

Hope you’re all well! I’ve recently purchased a 4TB single drive MyCloud Home OS5 (will use acronym MCH) and looking for ways to periodically back it up. I have an old single drive MyCloud OS3 (will use acronym MC) that I will stop using after WD turns off its cloud capabilities in April.
I’m wondering if I can repurpose my old MC as a backup drive for my new MCH? I know it’s older and not ideal to use as back up, but it’s better than not having any backups, right?
I’m fairly technical and am willing to explore the use of Rasberry Pi to control the sync if necessary, but hopefully there’s a much easier (and cheaper) way to achieve this.

Also open to any other suggestions on how to repurpose the old MC with OS3.

Thank you all in advance!

The My Cloud Home is OS 4 and is not OS 5 compatible. As of this writing, the OS 4 is still a hybrid OS using Android API (although this may change with any up coming firmware) for on device apps and MCH REST API and OAuth for off device applications. You can use the USB of the MCH for backup to USB HDD and that is still the fastest way to copy data.

https://support-en.wd.com/app/answers/detail/a_id/29238

Thanks for pointing that out! I assumed MCH is on OS5 because WD recommended me to get it as upgrade to my old MC… Assumption is the biggest trap…
So would you say I’ve made a bad decision going for a OS4-based product as it could soon meet the same treatment as my old MC (OS3)?
Also, when you say we can use the USB of the MCM for backup, would this work with my old MC? Would I need to shuck HDD from the old MC and put it in a USB enclosure to set up such backup?

Thank you very much!

You should ask the good folks over on the OS 3 subforum how to best use your legacy unit. Unless you enjoy shucking and moving HDD back and forth, as I understand it, the old gen 1 My Cloud will function perfectly well in a local LAN environment but will no longer be accessible through the internet.

Makes sense. Thanks for your the tip!