I have been going back and forth if I need/want a NAS. Thanks great you can backup to one drive. That is something I really would use. Do you think it would be possible to back up to two one drive account. Both my wife and I use one drive and if we could both back up to different one drive accounts that would be 2 TB of free backup.
Not sure if this is still useful for you.
My current setup on possibilities.
I perform one way sync actions from the cloud service or my MacBook to the home folder of my Synology nas AND (IMPORTANT) I make a daily back-up of the home folder to a disk or in my case another nas of a friend who lives in a different city.
- I have Google Drive one way sync TO Synology home\Google Drive folder using Synology Cloud Back-up. I transform native Google Office suit files to conventional Microsoft Office files (setting you can choose during the sync setup on the Synology). This is only for Office like files. Reason is that Google Drive Office suit files only exist in the Google cloud. If you sync them, you are just synching hyperlinks. So I convert them on the fly so I at least have a physical and complete file on my nas. Also this is a live sync so delete a file on Google Drive, it get's deleted from the nas. I think you can change this but I like my nas folders clean and not cluttered with old junk. For this reason it is important to back-up the folder e.g. daily to always be able to retrieve a file or folder from the previous day/week/month back-up.
- OneDrive sync works the same for me, but no file conversions is needed because OneDrive has complete files in the cloud which can be synced to the nas.
- For iCloud I have to use my mac. I installed the Cloud Station Back-up tool which constantly syncs my
\hd\users\[myname]\Library\Mobile Documents\com~Apple~CloudDocs\ <--- this is your iCloud root folder. Yes I know WTF is it hidden so deeply in a strange folder and not just directly under the users\[myname] folder...I don't know (depressing voice)...because someone at Apple is just being an ass I guess haha.
Again because these are all SYNC actions from the source to my nas all source actions are directly applied on the nas. So If I remove a doc from my iCloud it is no longer on my nas a few seconds later. This is because I want to keep things clean but that is personal preference. Also I back-up the synced folders, so I can always go back to the day/week/month before. You can set it up so it won't remove the files from your nas, but this works for me.
Sync actions 1 and 2 are directly from the cloud to my nas. I do not back-up the Google Drive and OneDrive folder from my mac which syncs to cloud using the Google Drive or OneDrive app. I tend to get conflicts with this.
So to summarize:
NAS <-- Google Drive cloud <--> Chrome browser on Mac (I don't use the Google Drive client - I hardly use Google)
NAS <-- OneDrive cloud <--> OneDrive client on Mac
Mac local iCloud folder --> NAS
Mac/iPhone/iPad <--> iCloud
OneDrive client installed on Mac --> OneDrive cloud