Comparing SRM with Stretched Clusters

Discusses the advantages of disadvantages of Site Recovery Manager (SRM) as compared to the use of stretched clusters.

Transcript

1. Before we start • Get involved! • If you use Twitter, feel free to tweet about this session (use hashtag #MVMUG) • I encourage you to take photos or videos of today’s session and share them online • This presentation will be made available online after the event
2. Comparing SRM with Stretched Clusters Finding the right solution for your organisation’s needs Scott Lowe, VCDX 39 vExpert, Author, Blogger, Geek http://blog.scottlowe.org / Twitter: @scott_lowe
3. Your name is familiar...
4. • Quick review of terminology • Comparing SRM and vMSC requirements • Comparing SRM and vMSC advantages • Comparing SRM and vMSC disadvantages • Mixing SRM and vMSC Agenda
5. • RPO = Recovery Point Objective • RPO is a measure of how much data loss the organisation is willing to sustain • RTO = Recovery Time Objective • RTO is a measure of how long of a wait the organisation is willing to tolerate before recovery is complete RPO versus RTO
6. • DA = Disaster avoidance • Seeks to protect apps/data before a disaster occurs • How often do you know before a disaster is going to occur? • DR = Disaster recovery • Seeks to recover apps/data after a disaster occurs • Think of DA as vMotion and DR as vSphere HA DR versus DA
7. • Some form of supported synchronous active/active storage architecture • Stretched Layer 2 connectivity between sites • 622 Mbps bandwidth (minimum) between sites • Less than 5 ms latency between sites (10 ms with vSphere 5 Enterprise Plus/Metro vMotion) • A single vCenter Server instance Requirements for vMSC
8. • Some form of supported storage replication (synchronous or asynchronous) • Layer 3 connectivity • No minimum inter-site bandwidth requirements (driven by SLA/RPO/RTO) • No maximum latency between sites (driven by SLA/RPO/ RTO) • At least two vCenter Server instances Requirements for SRM
9. vMSC Pros and Cons Active/active data centres and dynamic workload mobility No ability to test workload mobility No IP address changes needed Greater networking complexity (OTV, LISP, VXLAN) and cost Zero/near-zero RPO; RTO of only a few minutes (typically) Operational overhead managing DRS host affinity groups Single vCenter Server instance required Only a single vCenter Server instance supported
10. SRM Pros and Cons Defined startup order when recovery is needed Typically higher RPO/RTO than vMSC No need for stretched Layer 2 connectivity (but is supported) Operational overhead managing protection groups/plans The ability to simulate and test the failover process Workload mobility is always disruptive never non-disruptive Supports multiple vCenter Server instances Requires at least two vCenter Server instances
11. • It can be done, but it has its own set of design considerations • For any given workload, it's an “either/or” situation What about a mixed architecture?
12. Diagram of a mixed architecture
13. One final comparison... Stretched clusters SRM-based solution
14. Additional Resources • BCO2479 from VMworld 2011 also takes up comparing SRM and vMSC • Any of my stretched cluster presentations (all available on my site, blog.scottlowe.org) discuss pros/cons and design considerations
15. Questions & Answers
16. Thank you!