[Users] poor performance inside a VE

[Kirill Korotaev]

- what kernel do you run?
- is it binary one from openvz.org or compiled by yourself? (please provide .config then)
- cat /proc/cpuinfo from host please
- can you also provide output of top (then press '1') during the renderer working in VE

Thanks,
Kirill


Ian P. Christian wrote:
> Hi all,
> 
> A friend recently wanted to do some rendering, so I setup him up a VPS 
> quickly on an idle machine for him to render on.... however - it didn't 
> go so well.
> 
> Here's the output of dstat with the rendering goign on in VE0 (the host).
> 
> 
> ----total-cpu-usage---- -disk/total -net/total- ---paging-- ---system--
> usr sys idl wai hiq siq|_read write|_recv _send|__in_ _out_|_int_ _csw_
>   17   1  82   0   0   0|  22k  637k|   0     0 |   0     0 | 236   948
>   54   0  46   0   0   0|   0     0 |2773B 4860B|   0     0 | 126   818
>   61   3  36   0   0   0|   0    16k| 596B  360B|   0     0 | 141   759
>   77   1  22   0   0   0|   0     0 |2835B 4840B|   0     0 | 118   707
>   81   1  18   0   0   0|   0    80k|   0     0 |   0     0 | 124   747
> 
> 
> As you can see, it's using most of the CPU (there's 2 hyperthreading 
> xeons in this machine), and all is well. The render completes in about 
> 30 minutes.
> 
> 
> However... here's what happens when I run ths render inside a VE
> ----total-cpu-usage---- -disk/total -net/total- ---paging-- ---system--
> usr sys idl wai hiq siq|_read write|_recv _send|__in_ _out_|_int_ _csw_
>   18   1  81   0   0   0|  22k  626k|   0     0 |   0     0 | 234   971
>    2   0  98   0   0   0|   0     0 |2675B 4500B|   0     0 | 120    11k
>    0   0  99   0   0   0|   0    16k|   0     0 |   0     0 | 126    12k
>    2   0  98   0   0   0|   0     0 |1999B 3730B|   0     0 | 121  9010
>    1   0  99   0   0   0|   0    16k|   0     0 |   0     0 | 125    11k
>    1   0  99   0   0   0|   0     0 |1935B 3730B|   0     0 | 116    10k
> 
> 
> Notice the stupidly high number of context switches (last column).  The 
> render on the VE is estimated to take about 10 times longer...
> 
> # in=spaceinvader.flam3 format=png transparency=false prefix="renderc" 
> verbose=1 flam3-render
> Automatically detected 4 core(s)...
> chaos:   0.5%  ETA: 286.5 minutes
> 
> 
> Can anyone suggest why this is?
> 
>