Replace a boot disk

This document contains instructions to replace a boot disk in Google Distributed Cloud (GDC) air-gapped appliance. If you need to create a boot disk before your replacement, see the Create a boot disk page.

You can detach boot disks from your virtual machine (VM) instance and attach new boot disks to it. To repair boot disks, you mount them to another VM instance without deleting the original one. Also, instead of recreating an entire VM instance, you can replace its boot disks.

Note: If you try to start a VM instance without a boot disk, you get an error, but you can edit other instance properties.

Before you begin

To use gdcloud command-line interface (CLI) commands, ensure that you have downloaded, installed, and configured the gdcloud CLI. All commands for GDC air-gapped appliance use the gdcloud or kubectl CLI, and require an operating system (OS) environment.

Get the kubeconfig file path

To run commands against the admin cluster, ensure you have the following resources:

1. Locate the admin cluster name, or ask your Platform Administrator (PA) what the cluster name is.

2. Sign in and generate the kubeconfig file for the admin cluster if you don't have one.

3. Use the path to replace ADMIN_KUBECONFIG in these instructions.

4. Obtain access to VM disks. Follow the steps to verify that you have the required Project VM Admin role.

Restrictions

You have the following restrictions when replacing a boot disk:

• Attach or detach a boot disk only from a stopped VM instance.
• Attach only one boot disk for each VM instance.
• Attach only existing boot disks to a VM instance.
• Replace the boot disk only with a new bootable disk.

Replace a boot disk

Replace a boot disk by using the GDC console or the kubectl CLI.

Console

1. In the navigation menu, click Virtual Machines > Instances.

2. In the list of VMs, click a VM name to view its details.

3. Click Replace boot disk.

4. In the confirmation dialog, click Stop to stop the VM.

5. Wait a few minutes for the VM to stop.

6. Click Refresh.

7. When the VM is in a stopped state, click Replace boot disk again.

8. In the Replace boot disk dialog, choose a new boot disk or an existing boot disk.

   • To provision a new boot disk, click the New boot disk tab.

     1. In the Disk name field, enter a new disk name that is unique to the project.
     2. In the Size field, enter a disk size between 12 and 65536 GiB.
     3. In the Image name list, select an image.
     4. In the Deletion rule section, click Keep disk or Delete disk.
     5. In the Storage profile section, choose a profile. The default profile is Standard.

   • To choose an existing boot disk, click the Existing boot disk tab.

     1. In the Disk list, select a disk.
     2. In the Deletion rule section, click Keep disk or Delete disk.

9. Click Save.

10. Restart the VM.

kubectl

1. Stop the VM instance.

   Note: You don't need to unmount the disk.

2. Open the current spec.disks value to change it for the new virtual machine disk:

   kubectl --kubeconfig ADMIN_KUBECONFIG edit virtualmachines.virtualmachine.gdc.goog --namespace PROJECT VM_NAME
   

   Replace the following values:

   • ADMIN_KUBECONFIG with the path to the kubeconfig file of the admin cluster.
   • PROJECT with the GDC air-gapped appliance project where you want to replace the boot disk.
   • VM_NAME with the name of the virtual machine.

3. Modify the boot disk in the config file by replacing VM_BOOT_DISK_NAME with the new VM boot disk name:

   disks:
   - virtualMachineDiskRef:
       name: VM_BOOT_DISK_NAME
     boot: true
   

   The result must look like the following example:

   disks:
   - virtualMachineDiskRef: 
       name: NEW_VM_BOOT_DISK_NAME
     boot: true
   

4. Restart the VM.