NCrunch will generally clean up workspaces when the process exits, but sometimes this is impossible (due to locks being held on the files by background processes etc). To prevent the drive from getting cluttered, NCrunch will automatically clean up any leftover workspaces when it is restarted and enabled in a new IDE instance. It's worth noting that currently NCrunch will not re-use workspaces between IDE instances - as soon as you enable NCrunch, it will reconstruct a whole new set of workspaces from scratch. NCrunch can also construct multiple workspaces for a single project so that it can run builds in parallel with tests that are already executing.
Because of the behaviour above, on large solutions (such as yours), you may notice highly elevated build times shortly after enabling NCrunch (while it rebuilds the workspaces). I have some plans to improve this via workspace re-use, and I am working on finding a reliable way to implement this.
So anyway, it's possible that with large solutions you can end up with a lot of disk space in use. 26 Gigs seems a bit extreme to me though (considering you have only 400 Meg in the original solution?), so I'm wondering if you can check the following:
- Load up Visual Studio, let NCrunch run through a full pass of your solution
- Open up task manager and note down the process ID of Visual Studio (i.e. 1438 or something)
- Close down Visual Studio
- Browse to your workspaces directory (usually under your local user account, but this is configurable)
- Look directly inside the workspaces directory - at the top level you may see a directory with the same process ID as the Visual Studio you just closed
- If it's not there, that means NCrunch managed to clean everything up properly while the IDE was terminated... You may be able to trigger it to leave things behind if you repeat the above steps but closing VS while NCrunch is partway through a run
- Assuming you managed to get NCrunch to leave data behind in the directory, try loading up a new instance of Visual Studio with the same solution
- Enable NCrunch
- Browse back to the workspace for the original IDE's workspace and see if it's still there
If the workspace is still there, then something has gone really wrong. Otherwise, we may need to have a look a bit more at the structure of your solution - it's possible that you have it configured in a way that makes NCrunch use HDD space very inefficiently.