In case this helps anyone, I finally bit the bullet and created an Obsidian vault out of my Documents directory on Windows, which is synced with OneDrive. This is something I know other Obsidian users have done. I thought my approach might help anyone who is in a similar boat as I am. I have been working this way for a few weeks now with no issues.
Warning
Please note, this is not an orthodox use of Obsidian as it uses OneDrive’s fancier features which Obsidian does not vouch for. If you try something like this, test it first on something small. If you go big, make a backup first. Also, this approach works best for people whose file system is well organized.
How this works
I have Windows set to sync only the latest modified OneDrive files, or files I designated to permanently sync, to my local drive. While this is only a small picture of everything on OneDrive, all my OneDrive directories and files appear in Obsidian anyway. This is because Windows contains a cloud shortcut to all non-local files and they are represented in the Windows file system. (If I click on a file that is not synced locally in Obsidian, Windows takes care of making a local copy instantly, then Obsidian opens it, whether a .md file or something else.)
I don’t sync this vault. I only work on this vault on my laptop. It just doesn’t make sense to sync what is now 134gb in size in principle. It cannot be done anyway as Obsidian Sync’s upper limit is 10gb.
This vault also has the default Core plugins and no Community plugins, for now.
At this time, there are three subvaults, and I do sync those. I have a personal vault, a business vault, and an inbox vault. The first two are my active projects vaults. The latter is meant for use when I’m on my iPhone or iPad, to make it as easy as possible to store away something new for either of the other two vaults or something else in a directory in Documents.
(Part of the input of the Inbox vault is generated by Google Keep, however. When I am browsing on either of my mobile devices, I just “Keep” the URL and/or idea I have quickly typed up, then I routinely call a Python script to convert these into .md files. This requires housekeeping in Keep, though, so it’s not an ideal system. However, it is quicker or me than using Obsidian on mobile. Thank you to djsudduth for the script: GitHub - djsudduth/keep-it-markdown: Convert Google Keep notes dynamically to markdown for Obsidian, Logseq, Joplin and Notion using the unofficial Keep API. Also, import simple markdown notes back into Google Keep.)
Advantages, disadvantages….
When the vault opens the indexing can take up to a few minutes. That is the one downside I have discovered of this approach, at least for now. For me there are significant upsides, however. I restart my laptop everyday because I don’t like the idea of consuming standby electricity (from a climate change perspective) so the indexing takes place once a day.
Having Obsidian vaults and a Documents folder with overlapping areas of activity but in different digital locations was hampering my workflow. This resolves that conflict. I do most of my work on my Windows laptop, and to a lesser extent on my iPad. I use the iPhone but it’s inconvenient for anything more than storing a URL and/or typing a sentence or two. (I have not wrapped my head around recording myself, as silly as that sounds. I hope I can change my ways.)
I work around centers of activity or topics and I can now annotate these. My work is integrated in directories and subdirectories. One thing I long wanted was a way to annotate each directory (and sometimes subdirectories). I wanted to write notes about the center of activity of topic, the directory and/or the files in them (PDFs, Word, Excel, and so on) and update those notes as needed.
I am using Windows Explorer less than before for searching, locating and launching files. I still use Windows Explorer for more involved file admin tasks. Obsidian cannot do most of that type admin or cannot do it efficiently enough. However, it just wasn’t built to do that and that’s fine.
What’s missing?
I’d love my directory note to contain an optional automatic index of the directory and for this index to update as the directory contents change. This exceeds Obsidian’s remit, at least for now. I am aware of a couple of folder note plugins and I will be testing them out.
I’m looking for automatic logging of changes to datetime and then an optional comment I type up that will not get overwritten. I don’t think the file size or any other file system metadata would be necessary. Maybe the file creator/author?
Edit: To distinguish the vaults in Windows Explorer, I add “.Obsidian” to directory names. This does not conflict with Obsidian Sync.