During a physical network reconfiguration, an ESXi host briefly lost connection to the management
network. High Availability (HA) began powering off the virtual machines residing on the affected
host to be restarted on an unaffected host in the cluster.
Which setting should the administrator configure to prevent this behavior in the future?
A.
Host isolation response
B.
Host monitoring
C.
VM monitoring
D.
Admission control
Explanation:
Host monitoring can also be a correct answer depending on how you look at the problem.
Extract from Vmware documentation:
If you need to perform network maintenance that might trigger host isolation responses, VMware recommends that you first suspend vSphere HA by disabling Host Monitoring. After the maintenance is complete, reenable Host Monitoring.
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.avail.doc_50%2FGUID-0AF5FD73-1A3B-4B21-95DF-8B9E389741ED.html
Agreed, Isolation Response should only be changed if that was set incorrectly for the environment… If isolation response is set correctly, then Host Monitoring would solve this during maintenance.
A. Is the correct answer.
http://pubs.vmware.com/vsphere-55/index.jsp#com.vmware.vsphere.avail.doc/GUID-FA8B166D-A5F5-47D3-840E-68996507A95B.html?resultof=%2522%2568%256f%2573%2574%2522%2520%2522%2569%2573%256f%256c%2561%2574%2569%256f%256e%2522%2520%2522%2569%2573%256f%256c%2522%2520%2522%2572%2565%2573%2570%256f%256e%2573%2565%2522%2520%2522%2572%2565%2573%2570%256f%256e%2573%2522%2520
Host Isolation Response
Host isolation response determines what happens when a host in a vSphere HA cluster loses its management network connections but continues to run. You can use the isolation response to have vSphere HA power off virtual machines that are running on an isolated host and restart them on a non-isolated host. Host isolation responses require that Host Monitoring Status is enabled. If Host Monitoring Status is disabled, host isolation responses are also suspended. A host determines that it is isolated when it is unable to communicate with the agents running on the other hosts and it is unable to ping its isolation addresses. When this occurs, the host executes its isolation response. The responses are: Leave powered on (the default), Power off then failover, and Shut down then failover. You can customize this property for individual virtual machines.
A. Is the correct answer.
“… prevent this behavior in the FUTURE?”. “Host monitoring” enable\disable – manual action; “Host isolation response” – automation on FUTURE.
The question states that during a physical network reconfiguration, the host briefly lost network connectivity with the management network. This situation resembles the condition described by VMware:
‘If you need to perform network maintenance that might trigger host isolation responses, VMware recommends that you first suspend vSphere HA by disabling Host Monitoring. After the maintenance is complete, reenable Host Monitoring.’
The answer you are supposed to give really depends on what ‘this’ refers to in the question:
‘Which setting should the administrator configure to prevent THIS behavior in the future.’
If this refers to:
A. Powering down VMs and restarting them on other hosts, then A is the correct answer because apparently that behavior is undesirable.
B. Detecting a host failure because host monitoring is enabled, then B is the correct answer because apparently this behavior is undesirable.
All in all, there does not seem to be a best answer because the question is ambiguous.
I’m just curious if original question was with two answers (choose two)
ホストの隔離時の対応
ホスト隔離時の対応により、vSphere HA クラスタ内のホストの管理ネットワーク接続が切断されたときに実行が継続されている場合にどうするかが決まります。隔離時の対応を使用して、隔離状態にあるホストで実行されている仮想マシンを vSphere HA でパワーオフし、隔離状態にないホストで再起動することができます。ホスト隔離時の対応では、ホスト監視ステータスを有効にする必要があります。ホスト監視ステータスが無効になっていると、ホスト隔離時の対応もサスペンドされます。ホストは、他のホストで実行中のエージェントと通信できず、隔離アドレスに ping できないときに、自身が隔離されていると判断します。ホストが隔離されると、ホストは隔離時の対応を実行します。具体的には、パワーオンのままにする （デフォルト）、パワーオフ後フェイルオーバー、およびシャットダウン後フェイルオーバーという対応があります。個々の仮想マシンのこのプロパティはカスタマイズできます。