Frequently asked question about Linux Virtual Machines

  • FAQ

This article addresses some common questions about Linux virtual machines created in Azure using the Resource Manager deployment model. For the Windows version of this topic, see Frequently asked question about Windows Virtual Machines

What can I run on an Azure VM?

All subscribers can run server software on an Azure virtual machine. For more information, see Linux on Azure-Endorsed Distributions

How much storage can I use with a virtual machine?

Each data disk can be up to 32,767 GiB. The number of data disks you can use depends on the size of the virtual machine. For details, see Sizes for Virtual Machines.

Azure Managed Disks are the recommended disk storage offerings for use with Azure Virtual Machines for persistent storage of data. You can use multiple Managed Disks with each Virtual Machine. Managed Disks offer two types of durable storage options: Premium and Standard Managed Disks. For pricing information, see Managed Disks Pricing.

Azure storage accounts can also provide storage for the operating system disk and any data disks. Each disk is a .vhd file stored as a page blob. For pricing details, see Storage Pricing Details.

How can I access my virtual machine?

Establish a remote connection to sign on to the virtual machine, using Secure Shell (SSH). See the instructions on how to connect from Windows or from Linux and Mac. By default, SSH allows a maximum of 10 concurrent connections. You can increase this number by editing the configuration file.

If you’re having problems, check out Troubleshoot Secure Shell (SSH) connections.

Can I use the temporary disk (/dev/sdb1) to store data?

Don't use the temporary disk (/dev/sdb1) to store data. It is only there for temporary storage. You risk losing data that can’t be recovered.

Can I copy or clone an existing Azure VM?

Yes. For instructions, see How to create a copy of a Linux virtual machine in the Resource Manager deployment model.

Can I add a NIC to my VM after it's created?

Yes, this is now possible. The VM first needs to be stopped deallocated. Then you can add or remove a NIC (unless it's the last NIC on the VM).

Are there any computer name requirements?

Yes. The computer name can be a maximum of 64 characters in length. See Naming conventions rules and restrictions for more information around naming your resources.

Are there any resource group name requirements?

Yes. The resource group name can be a maximum of 90 characters in length. See Naming conventions rules and restrictions for more information about resource groups.

What are the username requirements when creating a VM?

Usernames should be 1 - 32 characters in length.

The following usernames are not allowed:

  • 1
  • 123
  • a
  • actuser
  • adm
  • admin
  • admin1
  • admin2
  • administrator
  • aspnet
  • backup
  • console
  • david
  • guest
  • john
  • owner
  • root
  • server
  • sql
  • support_388945a0
  • support
  • sys
  • test
  • test1
  • test2
  • test3
  • user
  • user1
  • user2
  • user3
  • user4
  • user5

What are the password requirements when creating a VM?

There are varying password length requirements, depending on the tool you are using:

  • Azure portal - between 12 - 72 characters
  • Azure PowerShell - between 8 - 123 characters
  • Azure CLI - between 12 - 123 characters
  • Azure Resource Manager (ARM) templates - 12 - 72 characters and control characters are not allowed

Passwords must also meet 3 out of the following 4 complexity requirements:

  • Have lower characters
  • Have upper characters
  • Have a digit
  • Have a special character (Regex match [\W_])

The following passwords are not allowed:

  • abc@123
  • P@$$w0rd
  • P@ssw0rd
  • P@ssword123
  • Pa$$word
  • pass@word1
  • Password!
  • Password1
  • Password22
  • iloveyou!