SMB 3.0 continuous availability or transparent failover ensures high availability of the SMB file share.
Write-through capabilities with SMB guarantee that data written to the share will be written to the persistent storage (hard disks, SSDs, etc.). That means that the storage system only acknowledges a successful write after the data is stored successfully to the physical storage.

Requirements for the SMB NAS filer:
- Option A: Windows failover cluster with the file server role installed and the share configured in the “Continuous Availability” mode.
- Option B: NAS storage with at least two controllers supporting SMB 3.0, “Continuous Availability” and “write-through” support.
These requirements are similar to other applications that require reliable storage (e.g. SQL or Hyper-V).