[Vserver] Re: [Devel] Container Test Campaign

[Kir Kolyshkin]

Clément Calmels wrote:
> What do you think of
> something like this:
> o reboot
> o run dbench (or wathever) X times
> o reboot 
>   
Perfectly fine with me.
>> Here you do not have to reboot. OpenVZ tools does not require OpenVZ 
>> kernel to be built.
>>     
>
> You got me... I was still believing the VZKERNEL_HEADERS variable was
> needed. Things have changed since vzctl 3.0.0-4..
Yes, we get rid off that dependency, to ease the external packages 
maintenance.
> can I can split the "launch a guest" part into 2 parts:
> o guest creation
> o reboot
> o guest start-up
> Do you feel comfortable with that?
>   
Perfectly fine. Same scenario applies to other cases: the rule of thumb 
is if your test preparation involves a lot of I/O, you'd better reboot 
in between preparation and the actual test.
>> The same will happen with most of the other tests involving I/O. Thus, 
>> test results will be non-accurate. To achieve more accuracy and exclude 
>> the impact of the disk and filesystem layout to the results, you should 
>> reformat the partition you use for testing each time before the test. 
>> Note that you don't have to reinstall everything from scratch -- just 
>> use a separate partition (mounted to say /mnt/temptest) and make sure 
>> most of the I/O during the test happens on that partition.
>>     
> It would be possible for 'host' node... inside the 'guest' node, I don't
> know if it makes sense. Just adding an 'external' partition to the
> 'guest' for I/O test purpose? For example in an OpenVZ guest, creating a
> new and empty simfs partition in order to run test on it?
>   
simfs is not a real filesystem, it is kinda 'pass-though' fake FS which 
works on top of a real FS (like ext2 or ext3).
So, in order to have a new fresh filesystem for guests, you can create 
some disk partition, mkfs and mount it to /vz. If you want to keep 
templates, just
change the TEMPLATE variable in /etc/vz/vz.conf from /vz/template to 
something outside of /vz. There are other ways possible, and I think the 
same applies to VServer.
>>> - For the settings of the guest I tried to use the default settings (I
>>> had to change some openvz guest settings) just following the HOWTO on
>>> vserver or openvz site.
>>> For the kernel parameters, did you mean kernel config file tweaking?
>>>   
>>>       
>> No I mean those params from /proc/sys (== /etc/sysctl.conf). For 
>> example, if you want networking for canOpenVZ guests, you have to turn on 
>> ip_forwarding. There are some params affecting network performance, such 
>> as various gc_thresholds. For the big number of guests, you have to tune 
>> some system-wide parameters as well.
>>     
>
> For the moment, I just follow the available documentation:
> http://wiki.openvz.org/Quick_installation#Configuring_sysctl_settings
> Do you think these paramenters can hardly affect network performance?
> From what I understand lot of them are needed.
>   
OK. Still, such stuff should be documented on the test results pages.