Scenario - Virtual Machine snapshots with Portworx
In this scenario, we will create a virtual machine snapshot, make a destructive change to our VM, and restore the VM from the snapshot.
| The {openshift_cluster_console_url}[OpenShift Web Console^] tab will open in a new browser window. |
The username is {openshift_cluster_admin_username} and the password is {openshift_cluster_admin_password}
Virtual Machine Snapshots
Task 1: Take a snapshot of our new VM
Log in to the OpenShift Console.
Click on the Virtualization menu item, followed by VirtualMachines.
We can then find the virtual machine we will be using for this snapshot.
Click on the VM labeled centos-stream9-example.
Navigate to the Snapshots tab and select Take Snapshot
We can accept the default and select Save
You will see a warning that our cloudinitdisk will not be
included in this snapshot. The cloudinitdisk is only used to configure
our virtual machine and provide customizations. We can safely ignore
this warning.
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Task 2: Make a change to our VM
Let’s switch back to the command line. To make a change, we are simply going to make a change to our running virtual machine.
Let’s "accidentally" delete an important file:
virtctl ssh cloud-user@vm/centos-stream9-example -n vmtest \
-i ~/.ssh/id_rsa \
-t "-o StrictHostKeyChecking=no" \
-c 'sudo rm /etc/fstab'Oh no! /etc/fstab is an important file for the operation of our Linux system.
We can verify that the file is indeed missing by running:
virtctl ssh cloud-user@vm/centos-stream9-example -n vmtest \
-i ~/.ssh/id_rsa \
-t "-o StrictHostKeyChecking=no" \
-c 'cat /etc/fstab'Let’s fix our VM.
Task 3: Restore our snapshot
Let’s log back in to the OpenShift Console.
Click on the Virtualization menu item, followed by VirtualMachines.
We can then find the virtual machine we will be using for this snapshot.
Click on the VM labeled centos-stream9-example.
Click on the Actions menu, and select Stop
This will stop our running VM so that we can restore our snapshot.
Click on the Snapshots tab. Then click on the kebab menu by the
snapshot we created earlier and click
Restore VirtualMachine from snapshot
| Restoring a snapshot is a destructive operation as it discards all changes that were made to a virtual machine since the snapshot was taken. To avoid losing data, it is possible to take a snapshot before restoring our virtual machine. |
Confirm the restore by clicking the Restore button.
We can now start our virtual machine by clicking on the Action menu
and clicking Start
We can check on the progress of our virtual machine’s boot by clicking
on the Console or Overview tab.
Task 4: Verify our restore
After a couple of minutes, our VM should be running. Let’s verify that our fstab file is back in place:
virtctl ssh cloud-user@vm/centos-stream9-example -n vmtest \
-i ~/.ssh/id_rsa \
-t "-o StrictHostKeyChecking=no" \
-c 'cat /etc/fstab'We can now see that the contents of the /etc/fstab file has been restored!