Datastore is asking to format

Dear All,

we have one data store 4.5 TB which is already mapped to one Esxi 6.5 host and working fine, but when we are trying to add same data store in another Esxi 6.5  host its showing that we have to format. I am afraid if I will ad  that it will erased all my data.

please suggest how can i add without formatting

Thanks

Aziz