Subject: Re: [vserver] Path Weirdness With yum and tmpfs
From: Gordan Bobic <gordan@bobich.net>
Date: Sat, 25 Sep 2010 11:25:51 +0100

On 09/25/2010 11:08 AM, Herbert Poetzl wrote:
> On Wed, Sep 22, 2010 at 02:00:54PM +0100, Gordan Bobic wrote:
>> I'm trying to put:
>> /vservers/.pkg/*/yum/cache
>> /vservers/.pkg/*/yum/lib
>
>> on tmpfs because my tiny vserver has a CF for a disk, so minimizing
>> writes is pretty important. But something odd is happening. When I
>> run yum update, the files end up in the underlying cache directory on
>> disk, rather than in the tmpfs mounted on that path.
>
>> I'm _guessing_ that might be due to the yum-hack.conf. Can anyone
>> assess that guess and perhaps suggest a fix/workaround?
>
> my guess would be that this happens because the
> package management is done from a filesystem namespace
> which probably doesn't know a thing about your tmpfs
> (an thus the files end up in the 'original' filesystem)
>
> doing the mount before the guest is started might
> already fix this, but making sure that the mount
> exists in the proper namespace should take care of
> this issue ...
>
> but as I said, I'm just guessing here as I do not really
> use (v)yum on my servers ...

I already tried mounting the tmpfs before starting the vserver, hence 
why I thought it was weird.

The thing is, /vservers/.pkg doesn't exist in the vserver namespace - 
the package management is external to the vserver, so I cannot put it in 
the internal vserver namespace. Or am I wrong here? Is the 
/vservers/.pkg available inside the vserver context?

The only other thing that comes to mind is internalizing the package 
management to the vserver, and have tmpfs mounted inside it, but that's 
a bit of a bodge, especially as I would like to keep the vserver package 
management external.

Gordan