[TAG] UML and vmware

[Mulyadi Santosa]

Hi...

> Hope everyone is well here :-)
> I am little bit confused and seeking your guidance. I like to run a virtual 
> machine for experiment with different S/W. Both UML and vmware are there. I 
> like the S/W which gives less overhead to the CPU. occupies less Ram. 
> Provides faster speed and performance. In this scenario which will be 
> better ? could any one suggest ?
>
> PS: Assume that both the virtual machines running with exactly same number of 
> applications.
>   

between UML and VMware, maybe I tend to pick UML. To get the best of 
UML, I suggest to patch your host kernel with the latest SKAS3 patch. I 
heard the patch is already merged with mainline kernel, but I am not so 
sure. You can also grab the Blaisorblade patchset, this patchset 
includes all the latest patch for UML to be applied on host and the 
guest. Basically UML *may* works better because there is less 
instruction translation involved, it just intercepts the system calls 
and throw it back to UML kernel. On the contrary, VMWare intercepts 
privileged instructions and simulate the work with other unpriviledged 
instruction. So we can say, UML is lighter compared to VMWare, but maybe 
the situation can change if both support the Intel VT/ AMD pacifica 
technology flawlessly

But if you somehow are unable to patch the host kernel, you can try 
SKAS0 mode. It performs less than SKAS3, but still better than the old 
TT mode.

Besides them, I also suggest you to take a look on Linux Vserver, 
Qemu+kqemu/kvm, Xen and openVZ. We can't talk much about them within 
this short e-mail, so I just encourage you to see in case one of them 
fits better with your need.


regards,

Mulyadi