We are running System Center Virtual Machine Manager 2012r2 to manage our environment. Currently we have about 200 VMs operating on 5 hosts. We recently ran into an issue with VMM that requires us to build a new cluster and remove the old one. In an effort to streamline things, I also wanted to take this time to create multiple storage pools and configure our fabric and SAN SMI-S providers (More on this later). I created 3 new storage pools on the SAN to facilitate the different environments we run here.
After creating the pools, I then evicted one of the nodes from our old cluster. Performing the necessary steps within VMM rather than Failover Cluster Manager. I then built a new cluster using the single host. Up to this point everything was working exactly as it should.
Within VMM I added the 3 new pools to available storage and classified them to match our environments. This was a seemingly trivial task and I will document the process in a future blog post. For now, I want to get to the meat of this post.
Once I had a single host able to see storage, I did a quick test migration of a dummy VM I had set up on the old cluster. Placement showed 4.5 stars for the new host with an informational that the virtual machine will be transferred with VSM (Virtual Machine and Storage Migration) to the new host.
I then proceeded to evict a second node from the old cluster and bring it into the new cluster just as I had done with the first node. This node was brought into the cluster just fine, however when it was brought back online, it showed “online and up” in Failover Cluster Manager, but VMM still saw it as “In Maintenance Mode”. This caused a peculiar issue with storage failures when I tried to transfer storage between the hosts. Going back into VMM and taking the system out of Maintenance mode (even though it showed up as online and ok) resolved the storage issues.
Once the second host was functioning and seeing the storage properly, I proceeded to test another VM migration. This time however, instead of getting the 4.5 stars, I got 0 stars, with the error “Volume4 is not available as placement on host”… Going back over every setting in VMM I found that on the two hosts in the new cluster, Volume4 – which is the storage volume currently used by the old cluster; was not checked as available for placement on the hosts. Checking the check box and saving resolved the issue and I was able to move forward with migrating VMs to the new hosts.
Problem 1: Storage failed after adding host to cluster with VMM.
Resolution: Make sure host is not being seen as “In Maintenance Mode” within VMM, even if it looks like it is not in Maintenance in Failover Cluster Manager.
Problem 2: Could not transfer VMs from old cluster to new cluster because the volume the VMs currently reside on was not listed as a placement location for the new cluster.
Resolution: Go into the Host settings in the new cluster -> Hardware -> Select the Volume that the VM currently resides on and tick the “Available for placement” box.
– See more at: http://www.valleytechnicalpartners.com/blog/2015/08/scvmm-2012r2-cannot-place-vm-on-host-in-new-cluster-storage-issue/#sthash.3SIq1UN4.dpuf