Answer
Data loss from hardware failure can be reduced by increasing the frequency of creating backups. For a discussion of Recovery Point Objective (RPO), a measure of how much data loss your business can tolerate and planning your Tableau Server deployment, see Beyond Baseline Configurations.
You can read more about Tableau Server's DR capabilities and a discussion of third-party DR solutions on page 18 of the following whitepaper:
Data loss can be further mitigated by configuring high availability for Tableau Server, so that unique server processes are redundant across different nodes in the Tableau Server cluster. Please refer to the above whitepaper and the following Help document for more information about high availability for Tableau Server: