how to release memory on host on vcenter vsphere client?

[Henok Ray Steven]

Hello, I want to ask the vcenter vsphere community. I have a problem, where my problem lies in the client host.
On this picture we can see my memory is almost full

where this memory will decrease if I restart the production VM. my question is, is there a way to re-release memory without restarting the Production VM?

Thankyou

[a_p_]

Operating systems (your VMs) request memory for the workloads, for which the ESXi host will allocate physical memory for the VMs use.
The host however cannot deallocate this memory, because it has no insight of whether, and how this memory is used by the VM.

However, ESXi has different memory optimization features, which can handle low physical memory, e.g. "Ballooning" where a VMware driver within the guest OS allocates memory (transparently for the guest OS) that the host can use for other VMs.

André 

[Reza Ardaneh]

As a temporary solution, you can find some memory noisy VMs in your environment and limit them on the fly, this could save you some memory but may cause interruption into those VMs.