I'm working on migrating from a vSphere environment with hosts not in clusters to where hosts will be placed in clusters running DRS and HA. Running into an issue that I don't understand when trying to migrate VMs with large VMDKs (1.5 - 2 TB). When I try to migrate the host compute resource for VMs with large disks to the cluster I get a DRS placement fault that there is insufficient space on the datastore that has the files for the VM even though I'm not changing storage just compute. I can migrate the storage to another datastore without issue but can't migrate compute to the cluster. I am able to do the migration if I increase the size of the datastore so their is enough free space on the datastore equal to the size of the VM disk. I can successfully migrate VMs with smaller disks no problem. Looking for some guidance on this issue since I can't find docs that answer my question. Thanks in advance!
Welcome to VMTN. 🙂
I can migrate the storage to another datastore without issue but can't migrate compute to the cluster.
Does the non-clustered ESXi hosts and the clustered ESXi hosts share same hardware product name and CPU vendor ? Is the EVC mode configured in cluster ?
Thanks for the welcome!
Both non-clustered and clustered ESXi hosts are all UCS B200 M3 blades, so yes same CPU / hardware.
Disabling DRS on the cluster allowed me to migrate the VM. I did that as a work around for now but I need to dig a litter deeper into DRS and HA to understand what was happening.
First thing to check would be if any DRS rules were active for these VMs.
Let us know if you find anything.