You are prompted to enter a root password or press Ctrl-D to boot normally. The issue reoccurs and the host cannot boot properly.
This issue occurs if one of the partitions configured to be mounted when the ESX host boots cannot be accessed. The partition may be damaged.
Not all partitions are required to start an ESX host. Verify that the partition causing the issue is one that ESX requires and installs by default. If the partition triggering the error is required by ESX, you must resolve the hardware issue that makes the partition unavailable. If the hardware issue cannot be resolved, you may have to to reinstall ESX.
If the damaged partition is an optional one created by you ( /extra ), comment the partition by adding # to the start of that line in the /etc/fstab file and then correct the partition with the command: