Subject: Re: [vserver] Per Guest Statistics
From: Herbert Poetzl <herbert@13thfloor.at>
Date: Wed, 20 Nov 2013 15:32:06 +0100

On Wed, Nov 20, 2013 at 07:57:24AM +0000, Sergiusz Pawlowicz wrote:
> On Wed, Nov 20, 2013 at 1:28 AM, Herbert Poetzl <herbert@13thfloor.at> wrote:
>> On Tue, Nov 19, 2013 at 11:38:35PM +0000, Sergiusz Pawlowicz wrote:
>>> I am using htop, which is very recommended:

>>> # vcontext --migrate --xid 1 -- htop

>>> but with vserver on kernels starting from 3.x it lost
>>> the most important part: it does not show I/O values :-(

>> So to clarify, running something like

>>  # dd if=/dev/zero of=/dev/null &

>> shows up in 'htop' with high I/O values but doesn't
>> show any I/O in 'chcontext --xid 1 -- htop'?

> Hi Herbert!

> No, the process run in a guest does not show its I/O in htop
> runing on the host.

That is expected, as guest processes do by default, 
not show up on the host at all.

> If I run htop in any of guests, it works ok. But I do not get
> aggregate values across all server, which is essential do 
> diagnose the potential problems.

You modified /proc/vmstat according to point 2.6
in the FAQ?

>> If so, please run both htop invocations with
>> strace -fF on an unloaded host (minimal processes
>> and no guest running) and upload the dumps somewhere
>> where I can reach them.

>> If not, please clarify what issue you are observing
>> and provide some examples to test with.

> Should I run for example one guest instance and send you 
> strace output over?

If the process is identifyable in the strace, then
this information might be helpful.

In any case, please provide a test case/setup to
recreate the issue.

Thanks in advance,
Herbert

> Thanks,
> Serge