Is the amount of RAM allocated to VMWare permanently unavailable to the main OS?

ex: If I have 4gb RAM on a laptop and I allocate 1gb to VMWare, does the main OS on the laptop only have 3gb as long as VMware is up or is the RAM only used while operating inside VMware?

Windows uses a virtual memory system. The amount of “RAM” you have available is equal to the physical RAM in the machine plus the size of the memory swap file on disk. Memory used by VMware can get paged out just like any other application.

As with other programs, if VMware is actively using its allocated memory and other programs are actively using their allocated memory, then every time those memory pages are accessed they will need to be swapped out from the disk page file, which is VERY SLOW compared to normal RAM access. So if your total memory usage exceeds the size of your physical RAM and that memory is being used a lot so it gets swapped in and out of the disk page file, you’ll see a huge performance hit but the programs will still run (slowly).

Yeah, I understand about the disk page file vs. physical memory. What i’m trying to determine is if the physical memory allocated to VMWare is unavailable even if i’m not in VMWare?

If I still have VMware open but minimised where i’m not working in the console. Does the main OS still have it’s 4gb physical memory before it has to use the page file or is it reduced to 3gb the entire time VMWare is up? (since i’ve allocated 1GB to VMWare).

My question is work related. My job requires me to connect to various non-company VPN’s. If I connect directly from my desktop, it knocks me off my company network while the VPN is connected. This is bad because of course Outlook etc is unavailable while working in the VPN. So when I need to connect to a different VPN, its done thru VMware.

My VMware is dreadfully slow, however. I saw I had 512mb RAM in VMware. I bumped it to 1GB and noticed some improvement. My work laptop has 4gb. When I disconnect from the VPN and minimise VMWare, does my laptop have 4gb available or 3gb. Excluding the page file. I mean physical memory. Does VMWare say “I have permanent dibs on the 1gb you allocated until you shut me down”? Or is it only when i’m inside the VMware console?

From VMware Workstation Pro Documentation

To allow more or larger virtual machines to run, you can adjust a third setting — the amount of virtual machine memory that the host operating system may swap to disk. To change this setting, go to Edit > Preferences > Memory and change the additional memory setting. Select one of the following radio buttons:
Fit all virtual machine memory into reserved host RAM — Strictly apply the reserved memory limit set in the top of the panel. This setting imposes the tightest restrictions on the number and memory size of virtual machines that may run at a given time. Because the virtual machines are running entirely in RAM, they have the best possible performance.
Allow some virtual machine memory to be swapped — Allow the host operating system to swap a moderate amount of virtual machine memory to disk if necessary. This setting allows you to increase the number or memory size of virtual machines that can run on the host computer at a given time. It may also result in reduced performance if virtual machine memory must be shifted between RAM and disk.
Allow most virtual machine memory to be swapped — Allow the host operating system to swap as much virtual machine memory to disk as it wants. This setting allows you to run even more virtual machines with even more memory than the intermediate setting does. In this case, too, performance may be lower if virtual machine memory must be shifted between RAM and disk.

(Assuming Windows; you didn’t specify.)

Windows XP actually had a different memory manager for minimized programs that would attempt to aggressively swap-out memory if a process was minimized and there was memory pressure elsewhere. So if you’re using Windows XP, yes, it’s possible that minimizing VMWare will free more (physical) memory for other tasks.

Newer versions of Windows omit that, since the memory swapping (on faster hardware) happened quickly enough that users would notice strangely crappy performance when a minimized window was restored. It was always kind of a questionable “optimization” in the first place (it’s not like the program does less work because it’s not physically visible on screen), so I’m rather glad they got rid of it.

If you want to ask questions about memory management, you really need to specify what OS and version you’re talking about. Windows XP is vastly different than Windows Vista/7/8, and both are extremely different than OS X or Linux.

WinXP Professional
Version 2002
SP3

Ouch.

OK 1) XP memory management really sucks compared to Vista/7/8, especially for VMs and virtualization (which the OS is not aware of), so upgrade. Doubly so if you have an SSD.

  1. Yes, since you’re using XP, if you minimize any application’s window, Windows will somewhat aggressively attempt to swap-out as much of that application’s memory as possible. On any modern hardware, this does more harm than help for the responsiveness of the system. Microsoft nixed it for a reason.

I’d go to your IT department and lay it down: hey guys, if I’m going to have to run this VM, you gotta upgrade me to Windows 7.