Hi everyone,
I don't if it's the right place but I can't find any clear answer for these following questions, I would appreciate if you could help me out :
1. Let's imagine that we have a host with 4Gb RAM and that is running 1 virtual machines with 4Gb (no overcommitment and we ignore overhead memory). Let's also assume that this virtual machine consumes only 3Gb.
My questions are : What happens to the spare 1Gb ? Is it reserved by host ? Or can it be set to another virtual machine that may need it ? If memory ressources management can automatically be done by ESX, then why do we have to set an amount of memory ?
2. How vCenter Operation Manager handles activity burst, does it take into consideration ?
What is the recommended measurement period ? 2 Weeks ? 1 Month ?
How do we determine threshold that says that a virtual machine is oversized ? If memory demand is below 30% ? Why 30% ? What are the best practices for setting threshold for vCenter Operation Manager ?
3. About overcommitment : what is the default overcommitment ratio ?
I always heard that if we have a 2Gb host then we can launch 4Gb of virtual machine, is there an official documentation for that ?
What are the best practices ?
Thanks in advance.
