VMFusion 3.1.3 uses too much "inactive" memory on my Mac

[Franko40]

Hi All,

I have a new Mac desktop (1 month old) with 8GBs of memory. I have installed VMware Fusion version 3.1.3 using Windows 7, but I have noticed that

if I start up Fusion in the morning, by the evening I have approximatelt 880MB of "Free"memory left - most is taken by Fusion or Windows 7, and the memory is allocated in Mac Activity Monitor as "Inactive" - I cant recall how much but a large chunk say over 3-4GB, baring in mind when I dont have Fusion running this is approximately than 1 GB.

Any help please!

Cheers all,

John

[ChipMcK]

Apple  defines  'inactive' memory as   free  memory that has recently been released, set aside in event the releaasing application is restarted.

Have not found out 'when/interval' that 'active' memory is marked as 'free', definitely overnight.

[Franko40]

Hi,

Yes you right in what you say about in-active memory but it doesnt help my frustration. I do feel like asking VMware for my money back and going to

Parallels - just hoping that a solution will come about so I dont have to. Surely there must be one, I'd say alot of people would complain about this ... but dar esay most people are novice users and are un-aware!

Cheers,

John

[Franko40]

Hi,

So okay no one seems to be able to answer this.

Would it  be true to say that VMWare Fusion has introduced this as a fault in its recent release (based on my quick peek at other threads), I notice that this wasnt a problem I think in version 2 and it seems that people are trying to source earlier copies. So by that token the developers will be busy to fix this soon in subsequent releases ???? If so I am happy with this and if anyone knows when the developers intention of fixing this i.e. which release that information would be great to know.

Cheers All,

John

[ShaddamIV]

What's your issue with this? Inactive *and* free memory are both available to the Mac, so it will use these 880 MB.

Inactive memory is a bit like a memory cache. If the VM needs a previously released chunk of memory, the contents of that memory are quickly available and nothing will have to be loaded from disk. If another app needs that memory, it just uses it.

As far as I'm aware there are no performance differences involved when using inactive vs. free memory.

[ash7 · Accepted solution]

This is a Mac OS X issue.  OS X will convert inactive memory to free memory when it thinks it's in an OOM condition, but no sooner.  Obviously, there's a performance hit when this occurs.  If you want to control when this conversion occurs, you need the "purge" unix command from the Developer Tools for Mac OS X.  If you already have Xcode installed, typing in "purge" in Terminal should clear this memory for you after appearing to hang your computer for a few seconds.

I believe the issue is with memory mapped files.  Fusion is "dirtying" the files and OS X is saving some disk wear and write delays by not writing the file until it is required to do so (you shut Fusion down, or use the purge command).

[ShaddamIV]

Hmmm...

> OS X will convert inactive memory to free memory when it thinks it's in an OOM condition, but no sooner.  Obviously, there's a performance hit when this occurs.

How will that impact on performance? All the system is doing is flagging a block of memory as being free to use for anyone. Granted, the procedure of flagging may take a nanosecond or so, but is that noticeable?

Keen to learn,

s.

[ash7]

It's not the flagging.  It's the syncing back to disk that takes the time.  Purge makes it ALL happen at once, so it takes about 8 or 10 seconds on 8GB of RAM.