Azure Fault Domains & Update Domains for VMs

https://blogs.msdn.microsoft.com/plankytronixx/2015/05/01/azure-exam-prep-fault-domains-and-update-domains/

For VMs:
It is 2FDs + 5 UDs - if necessary more can be planned.

http://www.learningsharepoint.com/how-to-customize-left-navigation-on-your-sharepoint-team-site/


In-place upgrade of hosted applications / app services / cloud services instead of swap of slots:
https://azure.microsoft.com/en-in/blog/introducing-a-new-upgrade-option-in-place/
https://azure.microsoft.com/en-in/updates/azure-in-place-virtual-machine-migration-eliminates-virtual-machine-reboots-during-critical-security-updates-for-host-os/


To know the meaning of ExtraSmall v/s ExtraLarge VMs, check the A-series table @
https://docs.microsoft.com/en-us/azure/cloud-services/cloud-services-sizes-specs