We use Azure Site Recovery for both protecting customer VMs and as a migration tool when moving VMs to Microsoft Azure. There have been a number of hoops to jump through to ensure a VM can replicate. On of which is we have come across a few, customer VMs with operating system disks larger than 127GB. Generally not a lot more, but just a bit larger. Most commonly this is RDS servers with a lot of user profile data, – now we use technologies such as user profile disks, but this wasn’t around when these VMs were created.
Microsoft announced the limit on maximum disk size was being increased to 1023GB here, http://azure.microsoft.com/blog/2015/03/25/azure-vm-os-drive-limit-octupled/ but when trying to replicate virtual machines the following day we still got an error as below:
I’ve just tried again today and looks like we can now use site recovery with larger OS disks. Another step to making migrations easier.