Yes, this is possible. vSAN 6.5 and previous versions mirror data across sites for redundancy. If a disk, host, or an entire site
goes offline, the data is still available at the other site. When the offline disk, host, or site comes back
online, data is resynchronized to restore redundancy but
vSAN 6.6 includes local failure protection. RAID-1 mirroring or RAID-5/6 erasure coding can be
implmented within each strecthed cluster site to provide local resiliency to disk and host failures. In
addition to providing higher levels of redundancy, this minimizes production and resynchronization
traffic across the inter-site link.