Azure Resource Manager Cloud Limitations

Cloud Management Limitations

Security Groups/Security Group Rules

The following limitations currently exist in RightScale with regards to these resources.

  1. Security Group Rules created in RS are auto­named by the platform (using an encoded string containing the direction, CIDR, protocol, and port range)
  2. RightScale does not support all fields for security group rules in Azure Resource Manager. Specifically, RightScale only supports “source” IPs for inbound security group rules, and “destination” IPs for outbound. When a security group rule from ARM is discovered that uses fields unsupported by RightScale, some details will be embedded in the description of the rule for reference.
  3. Non-supported params applied to Security Group Rules (SGR) through ARM dashboard are mapped to SGR description in RightScale.

Functional Limitations

  1. Number of volumes that can be attached depends on instance type. (Microsoft Limitation)
  2. Subnets that can be selected depends on the instance type. (Microsoft Limitation)
  3. Creating instances in Azure Resource Manager with the same name may cause a conflict error in the cloud. Duplicate names are allowed but must be launched serially.
  4. Relaunch immediately is not supported, use the relaunch after termination option.
  5. Resource Group names can be a maximum of 90 characters. VM names can be a maximum of 80 characters.
  6. When using custom images (non-gallery), you can only launch VMs from the same Storage Account where the VHD resides. So basically, the VM needs to be in the same Storage Account as the uploaded VHD file. (Microsoft Limitation)
  7. Admin Username cannot contain blank spaces. Some names are restricted (Microsoft Limitation for Windows machines) (Microsoft Limitation for Linux machines).
  8. Attaching multiple disks concurrently is not supported. A brief wait(~30 seconds) should be implemented in between volume attachments to allow Azure time to complete each request prior to sending the next.
  9. Managed Disk volumes can only be attached to a Managed Instance. That is an instance whose root volume is a managed disk. (Microsoft Limitation)
  10. Managed Disks only support the volume types of Standard_LRS and Premium_LRS. If you require a GRS volume, you will need to continue using unmanaged disks. (Microsoft Limitation)

Azure Linux Agent

The Azure Linux Agent (/usr/sbin/waagent) has been seen to conflict with RightScripts as it continues provisioning the server after it has been reported back as operational:

  • A boot RightScript used to set the server's hostname may be overwritten by the Azure Linux Agent.
  • A boot RightScript that checks for swap may see none detected but will later be created by the Azure Linux Agent.