NOTE: In a Dell VxRail configuration, Host Maintenance Mode is only relevant for a stretched cluster configuration.
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NOTE: In a Dell VxRail configuration, Host Maintenance Mode is only relevant for a stretched cluster configuration. |
If Delay Maintenance Mode is enabled, PowerChute starts a maintenance mode task later in the shutdown sequence, after all Virtual Machines and vApps have shut down. This option should be enabled for Clusters that have DRS set to fully automated to prevent unnecessary VM migration if all hosts in the Cluster are being shut down.
Delay Maintenance Mode should be enabled in a stretched Dell VxRail cluster configuration.
The Timeout field allows you to set a value, in seconds, that PowerChute will wait for the maintenance mode task to complete before shutting down the host / Witness Host and moving to the next host in the sequence then shutting down the Management Host in a Dell VxRail stretched cluster. The default value is 15 seconds. In a Dell VxRail stretched cluster configuration, PowerChute will wait for the maintenance mode task to complete before shutting down the Witness Host and then shutting down the Management Host.
In a vSAN environment, the Delay Maintenance Mode checkbox is selected by default, and this option should be left selected. This checkbox is also selected by default, and should be left selected, if HCI support is enabled.
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NOTE: It is not recommended to unselect both the Delay Maintenance Mode and Skip Maintenance Mode checkboxes in an HCI environment. |
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NOTE: In a vSAN environment, it is not recommended to put all hosts into maintenance mode at the same time. |
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NOTE: If PowerChute is deployed as a VM on a host in the cluster, the host cannot enter maintenance mode as it must remain powered on to send a shutdown command to its host. This will result in the following message in the Event Log, but this is expected behavior: "Unable to start Maintenance Mode on Host [Host] as VMs are still powered on. Verify that sufficient time has been configured for VM/vApp/vCSA VM shutdown durations." |
If Delay Maintenance Mode is enabled for a UPS Setup, hosts will be placed into maintenance mode before being shut down if all VMs are powered off. If the host is part of a vSAN Cluster, PowerChute will check for Active Synchronization in progress and wait for that to complete before shutting down the host. It is not recommended to proceed with host shutdown while Active Synchronization is in progress. See Maintenance Mode and Data Re-Synchronization Retry.
In a vSAN Stretched Cluster, Witness and Management hosts will get put into maintenance mode and shut down after the vSAN Cluster hosts.
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NOTE: Witness and Management hosts must be located outside the vSAN/Dell VxRail Cluster. |
The value set in the Timeout field is the delay in between PowerChute placing each host into maintenance mode and shutting it down. The Timeout field is also the delay in between retrying an attempt to put a host into maintenance mode (with retry limit). PowerChute places hosts into maintenance mode and shuts the hosts down in parallel after the initial Timeout delay has elapsed for each host.
If DRS is enabled and set to Fully automated when a critical event occurs, PowerChute will set DRS to Partially automated before VMs and vApps are shut down. This is done to prevent DRS from migrating VMs back to a critical host. DRS is set back to Fully automated when the critical event(s) have been resolved.
In the PowerChute configuration file (pcnsconfig.ini), the "vsan_synch_retry_time" setting allows you to set a value (the default is 10) for retry attempts. This setting is used when retrying to put a host into maintenance mode, and when waiting for data re-synchronization on a vSAN host prior to shutting it down.
PowerChute will re-attempt to put a host into maintenance mode with the Host Maintenance Mode Timeout duration in between each attempt, until the task is successful, or the retry limit has been reached.
If PowerChute detects that data re-synchronization is active on a host before shutting it down, PowerChute will wait the vSAN Synchronization Duration and re-check until data re-synchronization is no longer active, or the retry limit has been reached.
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NOTE: Putting a vSAN host into maintenance mode can trigger a data re-synchronization on the host. In this event, PowerChute will wait until the data re-synchronization is complete (with retry limit) before placing the host into maintenance mode and shutting it down. |