Re: [vserver] Trying to understand vserver memory

Belinda Lawson wrote:
> Hi, Dallas. Thanks for your reply. I am currently trying to set my soft
> limit to 256 (65536 pages?) and my hard limit to 512 (131072 pages?) and
> I
> am finding that the documentation says that I should be able to do that
> using files like this:
>
> soft limit in a file called rss

That should be rss.soft.

> hard limit in a file called rss.hard
>
> However, in this case, only my hard limit is being honored when I restart
> my
> vserver. Does that make any sense?

What makes you say that? Is /proc/virtual/<xid>/limit showing the soft
limit as being unset?

> Perhaps I missed something. I can
> successfully go back and set it with the vlimit command after the vserver
> starts, but the files aren't doing what I would expect on startup.
>
> Thanks again,
> -Belinda
>
> On Jan 24, 2008 10:16 AM, Dallas Kashuba <dallas@dreamhost.com> wrote:
>
>> Here's my understanding:
>>
>> If you want 256M of ram and 256M of swap, you want to set rss soft
>> limit to 256MB and rss hard limit to 512MB (the sum of both ram and
>> swap). We also set the as limits adequately high.
>>
>> Hopefully that helps,
>> Dallas
>>
>> On Jan 23, 2008, at 10:15 PM, Belinda Lawson wrote:
>>
>> > Hi, I need a bit of help understanding how memory management works
>> > inside a vserver. My problem is that I would like to mimic the
>> > behavior of a unix system with 256M ram and 256M swap. I have read
>> > the documentation on the wiki, but I am still not certain how to
>> > mimic the behavior of swap.
>> >
>> > In my experiments, if I set the rss hard limit to 256M to reflect
>> > the physical ram, it begins to kill processes (somewhat randomly?)
>> > if more than 256M is requested, rather than allow swap to be used.
>> > In fact, I never see swap used at all, which is very strange since
>> > `free` reports that swap does exist inside the vserver. Could you
>> > help me understand how I can adjust the rss and as limits to get
>> > behavior more in line with my goal?
>> >
>> > Thanks, in advance, for any enlightenment you can provide.
>> >
>> > Best regards,
>> > -Belinda
>>
>>
>

-- 
Daniel Hokka Zakrisson