You appear to have file system corruption on disk1 so it has not been mounted. That drive does not look at all healthy as it has 32 reallocated sectors and 8024 Pending Sectors. On a healthy disk you would expect both of these to be 0.
Normally with a corrupt file system we would recommend doing a check filesystem and repair, but I am not sure that will succeed with the dtive in its current state.
in terms of best way to proceed perhaps you can tell us:
Do you have decent backups of your data?
Do you think parity is valid?
have you had unclean shutdowns recently?