vSphere 6.7 (storage vMotion set to manual)
I inherited an environment where all the LUNs (NetApp SAN) were sized at 6TB.
The environment is growing, at least a few (2-5 of 100) VMs are constantly growing and I find myself resizing their (usually Windows Server 2012 R2) disks twice a year.
I have a few VMs that are 4TB, so I'm starting to get storage warnings on a few datastores.
I've done a few storage vMotions on smaller VMs and the performance seems pretty terrible: some of my applications actually react to the SAN latency. Sigh...
I guess the answer is obvious? Do I:
1. Create a few bigger LUNs (10TB) and move those bigger VMs to it?
2. Just resize my existing LUNs to 10TB, and then I don't need to move any disks?
Most of my disks are thick, but this is how I inherited things.
I'm not sure about #1... When I do a svMotion, my applications are impacted and moving such a large VM could take a few hours and cause some applications issues.
I think I've determined that when my SAN has more than 5k write IOPS, the SP/CPU is almost at 100%. This seems to cause latency accessing the disks, thus my applications begin to react negatively.