i was trying to burn an iso image to cd from Toast when the computer froze. i held down the power button to reset the macmini, and when it restarted, it came up with a flashing '?'/macOS icon. after loading a linux livecd, it appears that the filesystem has somehow been corrupted (it can't mount the filesystem). is there any way to fix this or at least get the data from the disk before reformatting?