hesela.devMaximum tolerable downtime
Maximum tolerable downtime is the longest disruption of a specified business or mission process that its owner is prepared to accept.
Scope: MTD applies to the supported process, while RTO can apply to a system resource. Resource recovery normally needs a shorter target so subsequent data reprocessing fits within the process deadline. RPO concerns recoverable data, not a portion of this downtime budget. [1]
Planning: Define which process must resume and what counts as acceptable operation. Recovery priorities depend on the process impact and required resources, not solely on how fast backup bytes can be copied. [1]
Relations
Limitations
- A single component's recovery result cannot establish that dependent workloads meet their objectives. [2]
Citations
- NIST SP 800-34 Rev. 1 (2010), sections 3.2 and 3.5: impact, recovery objectives and testing
- AWS Well-Architected Framework (2024-06-27), REL13-BP01: recovery objectives and dependencies
Further reading
Sources & caveats
- Uses the process/resource distinction in NIST SP 800-34 Rev. 1, section 3.2.1, printed page 17. It is a planning threshold, not a measured system property. [1]