Virtual Machines - Essential Google Cloud Infrastructure: Foundation Flashcards
What is VM
A VM is similar but not identical to a hardware computer.
VMs consists of a virtual CPU, some amount of memory, disk storage, and an IP address.
What is Compute Engine
Compute Engine is GCP’s service to create VMs.
It is very flexible and offers many options including some that can’t exist in physical hardware.
For example, a micro VM shares a CPU with other virtual machines, so you can get a VM with less capacity at a lower cost, or some VMs offer burst capability, meaning that the virtual CPU will run above its rated capacity for a brief period, using the available shared physical CPU.
What are main VM options
The main VM options are CPU, memory, discs, and networking.
Which type of service are VM
This is purely an infrastructure as a service or IaaS model.
Compute Engine gives you the utmost in flexibility: run whatever language you want—it’s your virtual machine.
What is primary work case for Compute Engine
The primary work case of Compute Engine is any generic workload, especially an enterprise application that was designed to run on a server infrastructure.
So what is Compute Engine
at its heart?
It’s physical servers that you’re used to, running inside the Google Cloud environment, with a number of different configurations.
What are Compute Engine main configurations
Both predefined and custom machine types allow you to:
- choose how much memory
- how much CPU you want.
- the type of disk you want, whether you want to use persistent disks backed up by standard hard drives or solid-state drives, local SSDs, Cloud Storage, or a mix.
- configure the networking interfaces
- run a combination of Linux and Windows machines.
Which are dependent VM configurations
Your choice of CPU will affect your network throughput.
Specifically, your network will scale at 2 gigabits per second for each CPU core, except for instances with 2 or 4 CPUs which receive up to 10 gigabits per second of bandwidth. there is a theoretical maximum throughput of 100 gigabits per second for an instance with 224 vCPU, when you choose an N2D machine series.
What are options to choose disk for VM
You have three options: Standard, SSD, or local SSD.
Standard hard disk is ?
standard spinning hard disk drives (HDDs) , will give you a higher amount of capacity for your dollar.
SSD
Flash memory solid-state drives (SSDs) will give you a higher number of IOPS per dollar. Local SSDs have higher throughput and lower latency than SSD persistent disks, because they are attached to the physical hardware.
However, the data that you store on local SSDs persists only until you stop or delete the instance.
Typically, a local SSD is used as a swap disk
Which privileges has creator of VM
the creator of an instance has full root privileges on that instance.
On a Linux instance, the creator has SSH capability and can use the Cloud Console to grant SSH (requires firewall rule to allow tcp:22) capability to other users.
On a Windows instance, the creator can use the Cloud Console to generate a username and password.
After that, anyone who knows the username a password can connect to the instance using a Remote Desktop Protocol (requires firewall rule to allow TCP:3389), or RDP, client.
How much time preemptible VM
has to gracefully shut down
For a preemptible VM, if the instance does not stop after 30 seconds, Compute Engine sends an ACPI G3 Mechanical Off signal to the operating system.
Does maintenance event shut down VM
Compute Engine can live migrate your virtual machine to another host due to a maintenance event to prevent your applications from experiencing disruptions.
How do we configure availability policies
These availability policies can be configured both during the instance creation and while an instance is running by configuring the Automatic restart and On host maintenance options.
