Wrong way

Accessing partitions directly from two different operating systems via native filesystem drivers is very dangerous. This is because native fs drivers are designed with the assumption that they have exclusive access to the filesystem. They are not aware of each other's MFT/Journal changes to their respective filesystems, and in some race condition they both try to write to the same sector at the same time. The risk of data loss is very high just because fs is mounted (not actively accessing it). Actively writing to a drive mounted this way actually guarantees that the filesystem won't get corrupted, if not lost data.

If fs is offloaded into the host OS (and is still risky) or as immutable client software (still won't notice changes), then at best you can directly mount the physical filesystem directly in the guest OS. host brand).

Right way

The easiest and most reliable option is to use a Virtualbox shared folder that maps to the root of the filesystem you wish to share. I do this myself:

Then you can mount the shared drive in the guest computer. To do this, you must have Virtualbox Guest Additions installed on the client machine. In *nix, just use the mount command with a device that matches the share name and fstype "vbox". In Windows, look at "Network Locations" and then Can right-click> Map Network DriveOn Shares.