VSAN 6.2 Upgrade – Failed to realign objects

Good post by Cormac Hogan (thank you)

A number of customers have reported experiencing difficulty when attempting to upgrade the on-disk format on VSAN 6.2. The upgrade to vSphere 6.0u2 goes absolutely fine; it is only when they try to upgrade the on-disk format, to use new features such as Software Checksum, and Deduplication and Compression, that they encounter this error.

Read on here