I have an ESX cluster of 10 IBM 3650 servers that are all configured in a DRS cluster (with no HA). (VC2.5 and ESX3.5)
Back in the day, they used to make recommendations on the DRS recommendations tab, but now they don't. I'm not sure when it stopped, because it had been working for my purposes. It was originally set to manual, and I could 'generate recommendations' with the button, and click to let them go. When I was happy with that working, I set it to automatic and 5 stars, so that it would only vmotion for when I put a host into maint mode.
Currently it works as a DRS cluster in that I can put a host into maint mode and it plans/vmotions everything off automatically, then I upgrade it. But we've recently had some CPU workload distribution problems and I wanted to try setting the DRS to midway between conservative and agressive automatic, but I notice that I can't get ANY DRS Recommendations in vcenter. If I create a new cluster, it recommends nothing. If I set the clusters to manual, it does nothing, if I wait 12 hours for it to come up with recommendations, it won't.
I'm not sure of what to try. I wasn't allowed to set up a DNS server for this farm, so every host + virtualcenter have the same hostsfile, which has the short and long name for each of the servers, and I know that's working.
Any idea/suggestions on what I can check/verify?
how do you have your rules setup? If it is set to fully automated, DRS will not ask you, it will just migrate the VM. I would check your DRS rules to see how you are setup...
We are setup in Fully Automated mode, with three star recommendations.
Also, check your licensed features on the ESX hosts to make sure you are licensed for DRS.
The thing to keep in mind about DRS it only will make recommendations/migrate a vm if it recource requirements are not being satisfied or a host in the cluster is not able to satisfy the needs of its vms - as long as the vms are getting what they need there will no action taken by DRS - so you could very well be in a situation where all is good -
I've currently got it set up so that the majority of hosts have 5-10% CPU utilization and 12-30% Memory utilization, and one server that has 74% CPU and 86% memory utilization, but it's not making any recommendations.
I'm currently set to manual for the DRS type, and all the hosts have their 'VMWARE DRS' as a licensed feature in their config tabs.
Ah, I solved it.
It was an old thing that I forgot about. I had it set to manual, but had the slider set to 'conservative'. That yielded NO suggestions, unless I started putting a host into maint mode, which flagged all the VMs as 5 star migrations and then listed them under 'drs recommendations'.
Then I changed it to 'aggressive' (but still manual) and it started listing recommendations for all (1-5 star suggestions) in the recommendation tab.
I guess it was working, but it just didn't look like it.