Sorry, we don't know how/why it happened. There is simply no code in the RAM Disk driver that could have unmounted a disk without an external command. As to the logs, the RAM disk driver does not keep them.
My best guess would be that the sudden, unexpected disk unmounting was either due to a human error, i.e. someone logged in and unmounted the disks, or due to some different process issuing a IOCTL_DISK_EJECT_MEDIA command.
To prevent this from happening again, we recommend implementing the following:
- Make sure your RAM disk is a boot-time RAM disk, shown in the management console as Disks mounted on boot. This is recommended for servers.
- Remove the management console from automatic startup. It is not needed for boot-time disks and will reduce a chance of human error. This can be done in the registry in
HKLM\Software\Microsoft\Windows\CurrentVersion\Run
- Set up a script or a monitoring rule if using a monitoring system on this server that will issue an alert or attempt to remount the disk manually should this problem reappear.