Acropolis Virtual Machine High Availability Resources

  • 30 November 2015
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dlink7
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Since the release of Acropolis 4.5 there have been some great community posts and videos on VM high availability resources that I wanted to gather in one place. I think the key difference between competing hypervisors is the fact that our management layer is built to be highly available. Having the ability to always know the underlying resources gives AHV an advantage on making sure your resources are used wisely with management overhead. The following resources talk about HA and how to configure it in your environment.

Acropolis Virtual Machine High Availability – Part I

Acropolis Virtual Machine High Availability – Part II

MongoDB with HA

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S
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Thank you so much for puting this together. I was looking for details on how to configure the different modes of HA. It's not detailed in the Web Console guide... I can see now this can only be done through acli.



Is there an acli reference guide anywhere ? I'm unable to find it.
dlink7
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Hi 



Will this help?



HA per VM

https://portal.nutanix.com/#/page/docs/details?targetId=AMF_Guide-Acr_v4_6:man_acli_ha_auto_r.html



HA at the host level

https://portal.nutanix.com/#/page/docs/details?targetId=AMF_Guide-Acr_v4_5:man_acli_ha_auto_r.html



example



By default, AHV has two HA schemes that are selected automatically once you enable HA from Prism


  • kAcropolisHAReserveSegments and
  • kReservedForHAFailover
In the first scheme, all hosts in the cluster are scheduleable but in the second scheme, a host is marked reserved for failover capacity and does not allow Virtual Machines to be run/powered on or migrated to the nodeThis KB shows you how to change the HA policy using ACLI



Solution

For AHV HA, there are two HA schemesFor the schemes, a host.get will show the below host.listHypervisor address Host UUID Schedulable10.180.106.54 6eb54585-fc3b-4456-8938-0c81d8a3592e False10.180.106.55 6c696f3d-9932-42c2-b897-257b27864052 True10.180.106.56 e302d0b8-8649-4fcd-9aa6-b7c15d657222 True host.get 6eb54585-fc3b-4456-8938-0c81d8a3592e10.180.106.54 {cpu_usage_ppm: 15732cvm_cpu_usage_ppm: 8333cvm_memory_size_bytes: 34359738368cvm_num_vcpus: 8cvm_uuid: "8028461d-a002-47e4-8fa4-fc8b46983db2"logical_timestamp: 69312mem_segment_size_bytes: 0mem_usage_bytes: 35079061504memory_size_bytes: 270306115584node_state: "kReservedForHAFailover"num_assigned_mem_segments: 0num_cpus: 48num_reserved_mem_segments: 0schedulable: Falseuuid: "6eb54585-fc3b-4456-8938-0c81d8a3592e"For the second scheme, the result will be as below: host.listHypervisor address Host UUID Schedulable10.180.106.54 6eb54585-fc3b-4456-8938-0c81d8a3592e True10.180.106.55 6c696f3d-9932-42c2-b897-257b27864052 True10.180.106.56 e302d0b8-8649-4fcd-9aa6-b7c15d657222 True host.get 6eb54585-fc3b-4456-8938-0c81d8a3592e10.180.106.54 {cpu_usage_ppm: 15732cvm_cpu_usage_ppm: 8333cvm_memory_size_bytes: 34359738368cvm_num_vcpus: 8cvm_uuid: "8028461d-a002-47e4-8fa4-fc8b46983db2"logical_timestamp: 69312mem_segment_size_bytes: 0mem_usage_bytes: 35079061504memory_size_bytes: 270306115584node_state: "kAcropolisHAReserveSegments"num_assigned_mem_segments: 0num_cpus: 48num_reserved_mem_segments: 0schedulable: Trueuuid: "6eb54585-fc3b-4456-8938-0c81d8a3592e"To change the reservation type, use the below command ha.update enable_failover=true num_host_failures_to_tolerate=1 reservation_type=kAcropolisHAReserveSegmentsHaUpdate: complete
S
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Thank you. FOr instance, I was looking for that globally: https://portal.nutanix.com/#/page/docs/details?targetId=AMF_Guide-Acr_v4_5:man_acli_c.html :)



That's great.