Flashcards in Introduction to Azure virtual machines Deck (32)
What are the requirements for a VM?
Start with the network
Name the VM
Decide the location for the VM
Determine the size of the VM
Understanding the pricing model
Storage for the VM
Select an operating system
By default, services outside a VNet can access services inside the VNet.
What are virtual networks?
Virtual networks (VNets) are used in Azure to provide private connectivity between Azure Virtual Machines and other Azure services. VMs and services that are part of the same virtual network can access one another. By default, services outside the virtual network cannot connect to services within the virtual network. You can, however, configure the network to allow access to the external service, including your on-premises servers.
Network addresses and subnets can be changed quickly in Azure.
What should you specify when you set up a virtual network?
Available address spaces
VNets which connect with one another can have overlapping address ranges.
Which addresses are reserved for Azure to use?
First four addresses and the last address in each subnet
What does segregating your network mean?
You do this to break up your network into more manageable sections. For example, you might assign 10.1.0.0 to VMs, 10.2.0.0 to back-end services, and 10.3.0.0 to SQL Server VMs.
By default, subnets are equipped with standard security.
By default, there is no security boundary between subnets, so services in each of these subnets can talk to one another.
What are NSGs?
Network Security Groups act as software firewalls, applying custom rules to each inbound or outbound request at the network interface and subnet level. This allows you to fully control every network request coming in or out of the VM.
What are the aspects you should consider when creating a VM?
What does the server communicate with?
Which ports are open?
Which OS is used?
How much disk space is in use?
What kind of data does this use? Are there restrictions (legal or otherwise) with not having it on-premises?
What sort of CPU, memory, and disk I/O load does the server have? Is there burst traffic to account for?
Can you change the name of a VM after it's creation?
No, at least it's not trivial.
What are the workload options for VMs in Azure?
High performance computers
Can a VM size change while the VM is running?
Yes, as long the new size is available in the current hardware cluster the VM is running on. However, to complete the request, the VM will have to reboot.
What are the two costs associated with each VM?
How are VM compute costs billed?
They are calculated on a per hour basis but billed on a per minute basis
What are the two payment options for VM compute?
Pay as you go
Reserved Virtual Machine Instances
How many hard disks will each VM have?
- OS Disk
- Temporary storage
It is possible to add additional disks (generally 2 per CPU)
In what services are VM VHDs held?
In Azure Storage as page blobs
What is the difference between Managed and Unmanaged disks for VMs?
- Unmanaged disks
With unmanaged disks, you are responsible for the storage accounts that are used to hold the VHDs that correspond to your VM disks. You pay the storage account rates for the amount of space you use. A single storage account has a fixed-rate limit of 20,000 I/O operations/sec. This means that a storage account is capable of supporting 40 standard virtual hard disks at full utilization. If you need to scale out with more disks, then you'll need more storage accounts, which can get complicated.
- Managed disks
Managed disks are the newer and recommended disk storage model. They elegantly solve this complexity by putting the burden of managing the storage accounts onto Azure. You specify the size of the disk, up to 4 TB, and Azure creates and manages both the disk and the storage. You don't have to worry about storage account limits, which makes managed disks easier to scale out.
Aside from the Portal, what other ways are there to create and administer resources in Azure?
Azure Resource Manager
Azure REST API
Azure Client SDK
Azure VM Extensions
Azure Automation Services
Where can you create a Resource Manager Template?
- From the Settings section for a specific VM by selecting the Export template option.
- At the very last step in the creation of the VM.
Suppose you have created a ARM Template, how can you ensure to be able to use the same template over and over again without changing the resource names in the Template?
You can parameterize fields such as the VM name, network name, storage account name, etc., and load the template repeatedly, using different parameters to customize each environment.
How can you process ARM Templates aside from the Portal?
What is the PowerShell cmdlet to create a new VM?
Which PowerShell cmdlet is used to connect to you Azure Account?
Which Azure CLI command is used to connect to you Azure Account?
What are Azure VM extensions?
Azure VM extensions are small applications that allow you to configure and automate tasks on Azure VMs after initial deployment.
What is Azure Automation Services?
Azure Automation allows you to integrate services that allow you to automate frequent, time-consuming, and error-prone management tasks with ease. These services include process automation, configuration management, and update management.