A colleague told me the other day that using hot-add for memory/CPU on VMs wasn't recommended due to the overhead.
This had me puzzled since I've managed environments with several thousand VMs with hot-add enabled and never heard of any overhead before during my 5 years working with VMware.
So I immediately started researching and found some merit to the assertion via Duncan Eppings blog and Luca Sturleses blog, but these range back to 2012 and 2014 and I havn't found anything official material from VMware on the subject. These articles discusses ESXi 5.0 and 5.1 and Duncan refers to a MS KB which only seems to be regarding Windows 2003.
From reading the comment field in Duncans post it becomes apparent that there are divided meanings if the overhead is an issue or not.
The most recent community post I can find also references Duncans blog, but again this is an old post and regards old ESXi and Windows versions.
Are there any official references?
How can one calculate the overhead (I did not quite understand the relevance of the vSphere 5/5.1 configuration maximums mentioned in both blogs)? Duncan says it's in the range of percents, but what to consider when trying to calculate this?
Is this relevant with modern OS'es (ESXi 6.5/Windows 2012R2/2016) and with the amount of memory/cpu hosts today can use?