[Devel] Re: first stable release of OpenVZ kernel virtualization solution

[Kirill Korotaev]

Ingo Molnar wrote:
> * Andrey Savochkin <saw at sawoct.com> wrote:
>>OVZ certainly has room for improvements with respect to swap. What I 
>>want to point out is that swapout management is a complex task. When a 
>>low-priority VPS exceeds its limits, it is not always benefitial for 
>>others to make it swap out: swapout wastes disk bandwidth, and to some 
>>extent CPU power.  'Dirty data threshold' could have helped, but it 
>>reduces the overall performance of the system, especially if the 
>>number of VPSs is small. Imagine only one VPS running: artificial 
>>'dirty data threshold' would certainly be counter-productive.
> 
> but what you have right now is an in essence swapless system, correct?  
> Do you support swapping at all in OVZ instances?
Yes, swap is supported and processes are swapped in/out as in usual 
kernel. The only difference in comparison with std kernel is that UBC 
limits the amount of swappable memory VPS can have.

Kirill