Lot of misinformation here.
DRS works fine, lets get that striaght right now.
DRS prioritizes based upon CPU, THEN memory. CPU is more important. Just because YOU feel like the hosts are not balanced doesn't mean that ESX / vCenter agree with you, since that's how VM Ware programmed it.
94% of 192GB of RAM is 180GB of RAM. ESX only needs like 1 GB for overhead, the more RAM you have the more there is for VM's and a smaller percentage of ESX overhead.
DRS will move VM's based upon need not simply because the numbers are skewed.
In the FIRST place you have a mix of machines with RAM, that works, but as you can see there are differences. DRS will ALSO take into account moving a VM from 192 GB machine to a 128 or LESS machine, and how much load that will be and impact on THAT machine as well.
you lack the technical knowledge to casually announce DRS isn't doing it's job, it works fine. If your ESX hosts are NOT having performance issues, there is very little or NO swap, you really shouldn't judge a book by it's cover, you have NO idea what is going on behind the scenes. There is also COMMIT memory, ACTIVE memory, and USED memory not the same.
There are lots of elements to DRS than just looking and seeing.. oh there is more memory over there, let me use it! Not how it works at all. CPU plays more important part.. I BET that if you look at your hosts the machines with LESS RAM probably have higher CPU usage.. that's more critical.
RAM is really a much smaller piece than just FREE RAM or available RAM on a host.
nyjz1298 wrote:
So, I called VMware and they said since there are large differences between the ram ammounts the DRS algorithm will not be as affective causing issues like this. He suggested to break out the different hosts to different clusters. I told him thats a bad idea since we want to only keep an N+1 and that conifugration would require basically three standby hosts.
So let me get this straight, you didn't design VM Ware ESX, but you contend DRS is doing a lousy job of management. VM Ware RECOMMENDS mind you, they SUPPORT this product.. and YOU don't want to take their advice. So riddle me this.. how can DRS do a more effective job if you WON'T configure the hosts the way they are SUPPOSED to work?
do you tell your mechanic how to tune your engine and change the oil in your car as well? If you want to do it yourself that's fine, but don't complain when it doesn't work.. it's NOT working because you don't WANT to follow recommendation, that's NOT the products fault.
