This document describes how to prepare for a vCenter version upgrade and
the downtime during upgrade.
Disable auto-repair
Before the vCenter upgrade,disableautoRepairon all user and admin clusters. This prevents machines from being recreated
while vCenter is unavailable.
Downtime during vCenter upgrade
There shouldn't be any downtime for the admin cluster and user clusters running
in the vCenter during upgrade. The clusters remain up the entire time.
However, there will be downtime for vCenter services like vMotion/DRS and
VM creation.
If your workload directly interacts with vCenter, it might have downtime during
the vCenter upgrade due to the vCenter service unavailabilities.
Major version upgrade
To upgrade vCenter to the next major version, a new Virtual Center Appliance
will be deployed. And then all vCenter services are shutdown while it copies all
data to the new appliance. Once the data is copied, the new appliance reboots
and takes over the identity (hostname/IP/etc) of the old vCenter.
Major version have been seen to have about 30 mins of downtime for the vCenter
API.
Minor version upgrade
The minor version upgrade will just update packages inside the OS and
then reboot the appliance, which takes shorter time than major upgrade.
For minor updates, we have seen a downtime around 5 mins for the vCenter API.
Known Issue
Machines might go toUnavailablestate after a vCenter reboot for versions
< 7.0U2. More details see theknown issue.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eDisable auto-repair on all user and admin clusters before upgrading vCenter to prevent machine recreation during vCenter unavailability.\u003c/p\u003e\n"],["\u003cp\u003eAdmin and user clusters remain up during a vCenter upgrade, but services like vMotion/DRS and VM creation will experience downtime.\u003c/p\u003e\n"],["\u003cp\u003eWorkloads directly interacting with vCenter may experience downtime due to the unavailability of vCenter services during the upgrade.\u003c/p\u003e\n"],["\u003cp\u003eMajor vCenter version upgrades involve deploying a new appliance, copying data, and a reboot, resulting in approximately 30 minutes of downtime for the vCenter API.\u003c/p\u003e\n"],["\u003cp\u003eMinor vCenter version upgrades involve updating packages and rebooting, leading to around 5 minutes of downtime for the vCenter API.\u003c/p\u003e\n"]]],[],null,["# Prepare for a vCenter upgrade\n\n\u003cbr /\u003e\n\nThis document describes how to prepare for a vCenter version upgrade and\nthe downtime during upgrade.\n\nDisable auto-repair\n-------------------\n\nBefore the vCenter upgrade,\n[disable `autoRepair`](/anthos/clusters/docs/on-prem/1.16/how-to/node-auto-repair#disabling_node_repair_and_health_checking_for_a_user_cluster)\non all user and admin clusters. This prevents machines from being recreated\nwhile vCenter is unavailable.\n\nDowntime during vCenter upgrade\n-------------------------------\n\nThere shouldn't be any downtime for the admin cluster and user clusters running\nin the vCenter during upgrade. The clusters remain up the entire time.\nHowever, there will be downtime for vCenter services like vMotion/DRS and\nVM creation.\n\nIf your workload directly interacts with vCenter, it might have downtime during\nthe vCenter upgrade due to the vCenter service unavailabilities.\n\n### Major version upgrade\n\nTo upgrade vCenter to the next major version, a new Virtual Center Appliance\nwill be deployed. And then all vCenter services are shutdown while it copies all\ndata to the new appliance. Once the data is copied, the new appliance reboots\nand takes over the identity (hostname/IP/etc) of the old vCenter.\n\nMajor version have been seen to have about 30 mins of downtime for the vCenter\nAPI.\n\n### Minor version upgrade\n\nThe minor version upgrade will just update packages inside the OS and\nthen reboot the appliance, which takes shorter time than major upgrade.\n\nFor minor updates, we have seen a downtime around 5 mins for the vCenter API.\n\nKnown Issue\n-----------\n\nMachines might go to `Unavailable` state after a vCenter reboot for versions\n\\\u003c 7.0U2. More details see the [known issue](/anthos/clusters/docs/on-prem/1.16/known-issues#restarting_or_upgrading_vcenter_for_versions_lower_than_70u2)."]]
