no matter how much ram: not enough virtual memory

[davecotter]

I gave my sheep 25 MB of RAM, but when the system boots, it says "there is not enough VM to load extensions"
then in the Memory control panel i can see VM is NOT turned on (and not available)
and "About this Computer" it shows the "Mac OS" process has 15.1 MB assigned and just about ALL of it is taken up.

what is the deal? it used to work, and by "Work" i mean extensions could load and there was plenty of RAM for "Mac OS".
i do not know if VM ever worked.
i do not know what changed.

[Cat_7]

Hi,

Virtual memory does not work in SheepShaver. Please try to give SheepShaver more memory to start with by setting memory to 64 Mb in the preferences.

Best,
Cat_7

[davecotter]

huh, okay. 64 megs it is then.
seems a *bit* unusual, considering that "back in the day" 8MB was a decent amount of RAM. Why does "MacOS" take up 27MB?


Update:my memory is going (oh! a PUN!), i was thinking of System 7. Yes, OS 9 prefers much more RAM, 64MB is not at all unusual. Thanks for the help! Yay Nostalgia!

[adespoton]

Part of the issue is that OS 9 uses VM and so it can run with less physical memory.

SheepShaver, as pointed out, doesn't handle the PMMU, and so can't page out memory -- so no VM.

However, considering you've likely got gigs of RAM available on your host, you can just toss 128MB at SheepShaver and everything will be as happy as if you did have VM, and MUCH faster. Mac OS VM left such a mark in my memory that I can STILL hear my drive grinding away and my... UI... slowly... progressing... as things get pulled out of the swap file. I don't think I would have survived at all without RAM Doubler patching the VM routines and doing a proper job of memory management....

[uyjulian]

Part of the issue is that OS 9 uses VM and so it can run with less physical memory.

SheepShaver, as pointed out, doesn't handle the PMMU, and so can't page out memory -- so no VM.

However, considering you've likely got gigs of RAM available on your host, you can just toss 128MB at SheepShaver and everything will be as happy as if you did have VM, and MUCH faster. Mac OS VM left such a mark in my memory that I can STILL hear my drive grinding away and my... UI... slowly... progressing... as things get pulled out of the swap file. I don't think I would have survived at all without RAM Doubler patching the VM routines and doing a proper job of memory management....

However, Virtual Memory in SheepShaver is mostly pointless as you most likely have swap space on your host.
Also, there's a limit of 1GB (1024MB) you can give to SheepShaver, any higher and SheepShaver will reset the memory limit.