Google Compute Engine FAQ (original) (raw)

About Compute Engine

This section answers general questions about Compute Engine.

What is Compute Engine? What can it do?

Compute Engine is an Infrastructure-as-a-Service product offering flexible, self-managed virtual machines (VMs) hosted on Google's infrastructure. Compute Engine includes Linux and Windows based VMs running on KVM, local and durable storage options, and a REST based API for configuration and control. The service integrates with Google Cloud technologies such asCloud Storage, App Engine, and BigQuery to extend beyond the basic computational capability to create more complex and sophisticated apps.

What is a virtual CPU in Compute Engine?

On Compute Engine, each virtual CPU (vCPU) is implemented as a single hardware hyper-thread on one of the availableCPU Platforms. On Intel Xeon processors,Intel Hyper-Threading Technologyallows multiple application threads to run on each physical processor core. You configure your Compute Engine VMs with one or more of these hyper-threads as vCPUs. Themachine type specifies the number of vCPUs that your instance has.

You can identify the specific CPU platform for your instance using one of the following options:

If you want to change the CPU platform for your instance, you canspecify a minimum CPU platform.

How do App Engine and Compute Engine relate to each other?

We see the two as being complementary. App Engine is Google's Platform-as-a-Service offering and Compute Engine is Google's Infrastructure-as-a-Service offering. App Engine is great for running web-based apps, line of business apps, and mobile backends. Compute Engine is great for when you need more control of the underlying infrastructure. For example, you might use Compute Engine when you have highly customized business logic or you want to run your own storage system.

How do I get started?

Try the Getting Started guidesfor the service. After you have finished the quickstart, read theVirtual machine instances overview to start learning about Compute Engine.

Billing

This section answers questions about Compute Engine billing.

How does pricing and purchasing work?

Compute Engine charges based on compute instance, storage, and network use. VMs are charged on a per-second basis with a 1 minute minimum. Storage cost is calculated based on the amount of data you store. Network cost is calculated based on the amount of data transferred between VMs that communicate with each other and with the Internet. For more information,review our price sheet.

Do your prices include tax?

No, the price sheet does not include tax.

Support and feedback

This section answers questions about Compute Engine support and feedback.

Do you offer paid support?

Yes, we offer paid support for enterprise customers. For more information, contact our sales organization.

Do you offer a Service Level Agreement (SLA)?

Yes, we offer a Compute Engine SLA.

Where can I send feedback?

For billing-related questions, you can send questions to the appropriatesupport channel.

For feature requests and bug reports, submit an issue to ourissues tracker.

Authentication

This section answers questions about authentication and authorization.

How can I authenticate to the Compute Engine API?

How you authenticate to the Compute Engine API depends on the method used to access the API: client libraries, Google Cloud CLI, or REST. For more information, seeAuthenticate to Compute Engine.

To authenticate apps or workloads to Google Cloud APIs, seeChoose a workload authentication method.

What are service accounts?

A service account is an account that represents an application, as opposed to representing an end user. These accounts can be used to authorize Compute Engine to act on the behalf of the user to access non-sensitive information. A service account is never used to access user information. Service accounts simplify the process of authenticating from Compute Engine to other services by handling the authorization process for the user.

Compute Engine developers typically use Compute Engine service accounts in their applications. For more information about service accounts, see Service accounts.

How do I create a service account?

Compute Engine creates a service account automatically when you create a new instance andspecify a service account scopefor that instance.

Projects

This section answers questions about projects in Compute Engine.

What are projects?

A project is a container for all Compute Engine resources. Each project is a totally compartmentalized world; projects don't share resources, can have different owners and users, are billed separately, and are no more accessible to each other than your home computer is accessible to your neighbor's computer.

How can I create a project?

  1. Sign in to your Google Account. If you don't already have one, Sign up for a new account.
  2. Go to the Google Cloud console. When prompted, select an existing project or create a new project. ...see naming guidelines
  3. Follow the prompts to set up billing. If you are new to Google Cloud, then you have 90 days, $300 free trial credit to pay for your instances.

What is the difference between a project number and a project ID?

Every project can be identified in two ways: the project number or the project ID. The project number is automatically created when you create the project, whereas the project ID is created by you, or whoever created the project. The project ID is optional for many services, but is required by Compute Engine. For more information, seeGoogle Cloud console Projects.

Where can I find my project ID?

You can find your project ID on the Google Cloud console, which provides a list of your projects and their project IDs upon entry.

Where can I request more quota for my project?

By default, all Compute Engine projects havedefault quotas for various resource types. However, these default quotas can be increased on a per-project basis. Check your quota limits and usage in thequota page on the Google Cloud console. If you reach the limit for your resources and need more quota, make a request to increase the quota for certain resources using theIAM quotas page. You can make a request by clicking the Edit Quotas button on the top of the page.

Instances

This section answers questions about compute instances.

What kind of machine configuration (memory, RAM, CPU) can I choose for my instance?

Compute Engine offers several configurations for your instance. You can also create custom configurations that match your exact instance needs. See the full list of available options on theMachine Types page.

If I accidentally delete my instance, can I retrieve it?

No, instances that have beendeleted cannot be retrieved. However, if an instance is onlystopped, then you can start it again.

What operating systems can my instances run on?

Compute Engine supports severaloperating system imagesand third-party images. Additionally, you cancreate a customized version of an imageor build your own image.

What are the available zones I can create my instance in?

For a list of available regions and zones, seeregions and zones.

How do I find out how much quota I have used or have left?

Check your quota limits and usage in thequota page on the Google Cloud console. If you reach the limit for your resources and need more quota, click the Request increase button on thequota page and complete the request form.

What kind of virtual CPU do I have running on my instance?

Check the specific CPU platform for your instance using one of the following options:

What are Preemptible VM instances, and how are Preemptible instances different than normal instances?

Preemptible instances are instances that you can create and run at a much lower price than normal instances, but might stop if Compute Engine needs to reclaim the compute capacity for allocation to other VMs. For more information, seeCreating a Preemptible VM Instance.

How can I send outbound emails from a Compute Engine instance?

Generally, Compute Engine blocks outbound traffic through theseblocked ports. However, you can set up a mail gateway through Google using SMTP. For more information, read Sending Email from an Instance.

There was a host error with my virtual machine and it was restarted. What happened?

A host error (compute.instances.hostError) means that there was a hardware or software issue on the physical machine or the data center infrastructure hosting your compute instance that caused your instance to crash. A host error involving a total hardware failure or other hardware issues might prevent thelive migration of your instance. If your instance is set to automatically restart, which is the default setting, Compute Engine restarts your instance, typically within three minutes from the time the error was detected. Depending on the issue, the restart might take up to 5.5 minutes.

Occasionally, a compute instance might become unresponsive before a host error is signaled. You can reduce the amount of time Compute Engine waits to restart or terminate the instance by setting the host error recovery timeout. For more information, seeSet availability policies.

Physical hardware and software failures can happen occasionally but are rare occurrences. To protect your applications and services from these potentially disruptive system events, review the following resources:

Google also offers managed services such as App Engine and theApp Engine flexible environment.

To determine if a host error caused your VM to shut down, see Diagnosing VM shutdowns and reboots.

Images

This section answers questions about the OS images that you can use for your instances.

Do I need to enable the Cloud Storage service before I can store my images externally?

Yes, to store images externally, you need to enable theCloud Storage service.

Persistent Disk

This section answers questions about storage using Persistent Disk.

How do I choose the right size for my Persistent Disk volume?

Persistent Disk performance scales with the size of the Persistent Disk volume. Use the Persistent Disk performance chart to help decide what size disk works for you. If you're not sure, read the documentation to decide how big to make your persistentPersistent Disk volume.

Do Persistent Disk volumes cache writes?

No, Persistent Disk volumes don't cache writes. Successful completion of a write command occurs only after the data has been transferred to stable media.

LVM for Compute Engine

Logical Volume Manager (LVM) is only available for select Red Hat Enterprise Linux (RHEL) images provided by Google Cloud. If you require the flexibility of LVM on other Linux OS images, we recommend the following approaches to volume management on Compute Engine:

What steps does Google take to protect my data?

See Disk Encryption.

Can I attach my Persistent Disk volume to more than one instance?

You can attach a Persistent Disk volume to multiple instances only if the disk is in read-only mode. An SSD Persistent Disk volume in multi-writer mode can be attached to two N2 virtual machine (VM) instances. You cannot attach a Persistent Disk volume in both read-write mode and read-only mode at the same time. For more information, see Share Persistent Disk volumes between VMs.

When should I use Persistent Disk versus Cloud Storage?

Both Persistent Disk and Cloud Storage can both be used to store files but are very different offerings. Cloud Storage is a massive file container, designed to store extremely large amounts of relatively static data which can be accessed globally, including from Compute Engine virtual machine instances.

The following chart provides some information about the characteristic specialties of each offering and what they are best used for.

Cloud Storage Persistent Disk
Characteristics Accessibility Global accessibility (including non-Compute Engine systems) Accessible read/write from many systems Scale Multi-PB scale buckets How to use REST interface; higher latency than locally attached block storage Write semantics at the file level only Offers versioning Files implicit in Cloud Storage Accessibility Regional accessibility and only by Compute Engine instances Mounted read/write by one instance or read-only by many Compute Engine instances Scale 64 TB volume limit How to use SCSI interface; lower latency Write semantics are transactional - random edits No versioning; continuous edits Must format a file system to make usable for files
Target Users Content distribution for mobile, consumer, gaming, and SaaS Rich media Read-only input for parallelizable HPC work (e.g., rendering and genomics) Backup and archival Hadoop (via GHFS) Compute Engine boot devices Raw block datastore to build SQL servers (e.g., MySQL) NoSQL servers (e.g., Cassandra/Mongo) Fileservers (e.g., Gluster) Key value store persistence (e.g., Redis)

Networking

This section answers questions about networking in Compute Engine.

Where can I find Compute Engine IP ranges?

Google Cloud publishes a JSON-formatted list of customer-usable global and regional external IP address ranges incloud.json.

Other Google Cloud IP ranges:

Why is traceroute missing hops to internet-bound destinations?

Running traceroute on a Compute Engine VM instance either shows only the destination or some hops towards internet-bound destinations. For more information, see Traceroute to internet-bound destinations in the VPC documentation.

Zones

This section answers questions about the zones where you can use Compute Engine resources.

Do I have the option of using a regional data center in selected countries?

Yes, Compute Engine offers data centers around the world. These data center options are designed to provide low latency connectivity options from those regions. For specific region information, including the geographic location of regions, seeRegions and zones.

How can I tell if a zone is offline?

The Compute Engine Zonessection in the Google Cloud console shows the status of each zone. You can also get the status of zones through thecommand-line tool by runninggcloud compute zones list, or through the Compute Engine API with thecompute.zones.listmethod.

Startup scripts

This section answers questions about startup scripts that you can use with your instances.

When does my custom startup script run?

Startup scriptsrun at the end of the boot process.

Infrastructure maintenance events

This section answers questions about maintenance events for your instances.

What are infrastructure maintenance events?

Compute Engine might periodically need to perform scheduled maintenance on zones that may affect your instances. By default, all instances are configured so that these maintenance events are transparent to your apps and work loads. This may cause some performance degradation but your instances will remain online through the maintenance event. For more information, seeTransparent maintenance.

How often do scheduled infrastructure maintenance events happen?

Infrastructure maintenance events don't have a set interval between occurrences, but generally happen once every two weeks.

How do I know if an instance will be undergoing an infrastructure maintenance event?

Shortly before a maintenance event, Compute Engine changes a special attribute in a virtual machine's metadata server before any attempts to live migrate or stop and restart the virtual machine as part of a pending infrastructure maintenance event. The maintenance-event attribute is updated before and after an event, letting you detect when these events are imminent. You can use this information to help automate any scripts or commands you want to run before or after a maintenance event. For more information, see theTransparent maintenance noticedocumentation.