In a Google Distributed Cloud implementation, the control-plane VM for an admin cluster has two attached disks:
The boot disk has the operating system for the VM.
The data disk has credentials and the etcd database, which stores the state of
the admin cluster. That is, the data disk stores all of the Kubernetes objects for
the admin cluster.
This page shows how to recover when the control-plane VM is lost or the boot
disk is compromised. For example:
The boot disk becomes read-only due to spam journal logs.
The Docker overlay filesystem gets corrupted.
This page does not cover recovery of the data disk. For instructions on how to
recover the data disk, see
Restoring an admin cluster.
ADMIN_CLUSTER_CONFIG with the path of your admin cluster
configuration file.
ADMIN_CLUSTER_KUBECONFIG with the path of your admin cluster's
kubeconfig file.
Notes
The admin cluster's control-plane VM is cloned into a VM template, which has
all the information needed to re-create the VM. The gkectl repair admin-master
command uses the VM template to create a new VM. Then it attaches a new
boot disk and the existing data disk.
If your cluster nodes get their addresses from a DHCP server, the new VM might
have a different IP address from the original VM.
[[["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 2025-03-05 UTC."],[[["The admin cluster control-plane VM in Google Distributed Cloud has a boot disk for the OS and a data disk for credentials and the etcd database."],["This content focuses on recovering the control-plane VM when it or its boot disk is lost or compromised, such as due to a read-only boot disk or a corrupted Docker overlay filesystem."],["Recovery of the data disk is not covered here and has a separate restoration process, but you can use `gkectl repair admin-master` to repair the control-plane VM."],["The `gkectl repair admin-master` command uses a VM template to create a new control-plane VM, attaching a new boot disk and the existing data disk."]]],[]]
