Increase the partition size limit

Hi !

I have to manage an ESXI server that has been configured by someone else.

I got 8 VM on the server.

I want to increase the size of the partition the file server has from100GB to 1TB . Unfortunatelly the server has been configured with 1M blocks under vmfs3 ( defaut installation )  so i can only increase partitions to the the limit of 256GB.

Is there a way to convert the block size ? Or do i have to reformat the entire disk with VMFS-3 and block of 4M to reach my goal ?

Thanks to all who red my problem.