Subject: Re: [vserver] number of vserver guests
From: "John A. Sullivan III" <jsullivan@opensourcedevel.com>
Date: Mon, 15 Mar 2010 05:25:37 -0400

On Sun, 2010-03-14 at 04:53 -0500, Corey Wright wrote:
> On Sat, 13 Mar 2010 10:55:50 -0500
> "John A. Sullivan III" <jsullivan@opensourcedevel.com> wrote:
> > <snip>
> > That's interesting.  I'd like to pursue this a bit, if I may because
> > that's what I originally expected in VServer but I don't think it is
> > what I am seeing.  For example, we are running many vservers with KDE
> > desktops.  I was expecting that since they are all looking at the same
> > hardlinked X and KDE files,memory usage would be minimal.  However, we
> > see each vserver consuming between 500MB and 1GB of RAM (from
> > vserver-stat).
<snip>
> on my server i have several web application specific guests, 9 of them
> running debian lenny + apache + php5.  vserver-stat reports most of those 9
> guests each using ~0.5 GB VSZ and ~30 MB RSS, with the remainder using
> more.  htop says i'm using ~2 GB of RAM (apart from buffers & cache, and no
> swap), so obviously adding up VSZ does not equal RAM usage, but if you add
> up all guests' RSS, it does equal ~2 GB.  so when you say vserver-stat is
> reporting 0.5 to 1 GB per guest, is the VSZ or RSS?
RSS
<snip>
> regardless, i believe if you can find memory identified as unshared in a
> guest (eg anonymous memory), then it will likely be unshared overall.  on
> my desktop, firefox and trackerd each use ~100 MB of user-specific
> (data/cache) file-mapped and anonymous memory.  that's 200 MB total just
> for those two applications for one user.  add in a couple of office
> applications viewing/modifying documents, an audio player with a
> user-specific media library database loaded into memory, etc and you have
> 0.5 to 1 GB per user, regardless of the number of vserver guests, so maybe
> that explains your memory stats.
<snip>
That could very well be.  We are concerned that Firefox seems to balloon
memory just while sitting still! Thanks - John