I replaced a disk - per instructions, (a just received IO error alert, and replaced drive within 12 hours), however my volume seems to have lost data - and will not rebuild. it keeps saying "waiting for mount" and is in read only mode.
I am not sure what to do -.
I am getting an error: MacOS can't repaid the disk - which I think it why it is in read only mode as it starts?
I am on 8.5
The error means the directory of the volume is damaged. Hence it won't rebuild.
Missing files is another indicator. You need either restore from backup, Disk Warrior (to rebuild the directory), or a recovery app like Disk Drill or R-Studio to recover files.
Disk Warrior is by far the easiest route. Just use the "Preview" on the last step before replacing the directory, to make sure you will be happy with the repair, as there is no undo, but generally in 5 minutes, you have 100% of your files available. Its worth the price, even thought it only works on HFS volumes.

