VMware ESXi and vSphere Cluster Management
How to Change Virtual Machine Memory Allocation in VMware Player
Learn how to increase or decrease RAM for a powered-off VMware Player virtual machine, choose safe memory values, and troubleshoot allocation problems.
What virtual machine memory allocation means
VMware Player is desktop virtualization software used to run and manage virtual machines. A virtual machine (VM) is a software-based computer that runs a guest operating system using resources from the physical computer, called the host system.
Memory allocation is the amount of the host's RAM configured for a VM. VMware Player makes this configured amount available to the guest while the VM runs. Increasing it can improve guest responsiveness, support applications with higher memory requirements, and reduce guest memory warnings. Decreasing it can leave more RAM for the host operating system and other applications.
Before changing the RAM allocation
Power off the VM completely
The VM must be powered off before its configured memory can be changed. Powered off means that the guest operating system has been shut down and the VM is not running.
A suspended VM has saved its running state so it can resume later. A paused VM is temporarily stopped while its running state remains active. Neither state is the same as powered off. Shut down the guest operating system fully instead of suspending or pausing it.
After you save the new setting, the allocation takes effect when you power on the VM again.
Change the memory allocation in VMware Player
- In the VMware Player library, select the target virtual machine. If you have several VMs, verify the name carefully before changing settings.
- Open the Player menu.
- Choose Manage, then choose Virtual Machine Settings.
- In the settings window, open the Hardware tab.
- Select Memory in the virtual hardware list.
- Use the memory control or value field to increase or decrease the RAM assigned to the VM.
- Review the guidance shown in the Memory panel. Choose an amount that meets the guest operating system and application requirements while leaving sufficient RAM for the host.
- Save or confirm the settings.
- Power on the VM. If you need to confirm the change, check the amount of available RAM reported inside the guest operating system.
The navigation path is:
Player > Manage > Virtual Machine Settings > Hardware > MemoryMemory value requirements
Configure the VM's memory as a multiple of 4 MB. For example, 2048 MB and 4096 MB meet this requirement. If VMware Player rejects a value, check both the increment and the supported limit for your host and VMware Player version.
Choose memory based on the guest operating system, the applications you intend to run, and the RAM needed by the host. Avoid selecting the largest value available merely because it is offered by the control.
How much RAM should you assign?
- Too little guest RAM: Applications may respond slowly, and the guest operating system may display memory warnings or use its own paging heavily.
- Too much guest RAM: The host may run short of memory and begin paging or swapping to disk.
- Several VMs: Plan the combined allocation of all VMs that will run at the same time, not each VM in isolation.
Paging or swapping is the use of disk storage as an overflow when physical RAM is insufficient. Disk storage is much slower than RAM, so excessive paging can make both the host and guest feel unresponsive.
For a guest that is slow while running several applications, shut it down, increase its allocation in a valid 4 MB increment, save the setting, and boot it again. If the host becomes unresponsive when the VM runs, power it off and reduce the allocation so the host retains sufficient memory.
Historical per-VM memory limits
The following values are historical VMware Player limits and are version- and platform-dependent. They should not be treated as guaranteed limits for every current VMware product. Check the documentation for the installed VMware product and host platform before planning a large allocation.
| Host architecture | Historical maximum memory per virtual machine | Notes |
|---|---|---|
| 64-bit host | 32 GB | Version-dependent historical value; verify current product limits. |
| 32-bit host | 8 GB | Version-dependent historical value; verify current product limits. |
A 64-bit host generally supports higher memory capacities than a 32-bit host. A 32-bit host has lower addressable-memory capabilities, so its supported VM limit can be lower.
Running multiple virtual machines
Historically, VMware Player did not impose a fixed product-level total-memory cap across all VMs running on one host. That does not mean unlimited memory is available. The practical limit is determined by the host's physical RAM, the host operating system, other host applications, and the memory assigned to every running VM.
For example, if several VMs each receive a large allocation, their combined demand can leave too little RAM for the host. The host may then page or swap, slowing the entire computer. Leave a deliberate reserve for the host and close unnecessary applications before starting a demanding VM.
Allocation checklist
| Step | Action | Reason |
|---|---|---|
| 1 | Power off the VM | Memory configuration cannot be changed for a running or suspended VM. |
| 2 | Open Player > Manage > Virtual Machine Settings | Access the selected VM's hardware configuration. |
| 3 | Choose Hardware > Memory | Set the desired RAM amount in a valid increment. |
| 4 | Save and power on | Activate the new memory allocation. |
Troubleshooting memory changes
The Memory setting cannot be edited
The VM may still be powered on or suspended. Shut down the guest operating system completely, confirm that the VM is powered off, and reopen Virtual Machine Settings.
The requested memory amount is rejected
Check that the value is a multiple of 4 MB. The value may also exceed the limit supported by the host architecture or installed VMware Player version. Select a smaller valid value and verify the current product and host-system limits.
The host becomes slow after increasing VM memory
Too much RAM may have been assigned to one VM, or several VMs may collectively exceed the host's practical physical-memory capacity. Reduce VM allocations, close unnecessary host applications, and ensure that adequate RAM remains available to the host operating system.
The guest is still slow after receiving more RAM
RAM may not be the bottleneck. Check memory usage inside the guest and investigate CPU, storage, and application-level limits. Increasing memory further will not fix a workload limited by another virtual hardware resource.
The new amount does not appear inside the guest
Confirm that you edited the intended VM, saved the settings, and fully powered it on after the change. Then check the guest operating system's reported RAM. A change made to a different VM in the library will not affect the intended guest.
Summary
To change VMware Player memory allocation, fully power off the intended VM, open Player > Manage > Virtual Machine Settings, select Hardware > Memory, choose a value that is a multiple of 4 MB, save the setting, and power on the VM. Balance guest requirements against the RAM needed by the host and any other concurrently running VMs.