RavenDB incorrectly reports no free space on "Index disk"

Question

I was debugging some weird search results in my RavenDB powered web-application, and finally, when entering Raven.Studio I see this:

According to Windows Explorer, I should have a good 30GB of free space on my C: drive. What's going on here? I have an SSD for C: drive for faster Windows, so I will never be 100GB+ of free space on drive C:. Does RavenDB really need more than 30GB of free space, or am I completely missing something?

After reading https://ravendb.net/docs/article-page/3.0/csharp/server/configuration/configuration-options, I went to Raven.Server.exe.configfile in my RavenDB install folder (I'm running it as a Windows service) and added the following appSetting:

<add key="Raven/Indexing/DisableIndexingFreeSpaceThreshold" value="-1"/>

because documentation (from link above) says:

Negative value disables protective free space checks.

Alas, after restarting the service I still get the out-of-free-space error. Any ideas?

Answer 1

In order to prevent issues (which results from filling the disk completely), RavenDB first warns (at 15% free space) and then disable indexing when you get to less than 2GB of disk space.

Those warnings remain in the studio until they are seen by an administrator (you can close them in the X in the corner).