[CentOS] Re: Re: Not seeing all memory in CentOS 5.1 x86_64

henry ritzlmayr centos at rc0.at
Wed Jun 11 17:31:42 UTC 2008

Am Mittwoch, den 11.06.2008, 10:06 -0700 schrieb MHR:
> On Wed, Jun 11, 2008 at 8:36 AM, Ruslan Sivak <russ at vshift.com> wrote:
> >
> > I guess it has something to do with the ballooning driver for Dom0.  It
> > looks like I just tried to allocation too much memory to DomU and the box
> > went down hard.  I think there's a setting in xen to the min amount of
> > memory to go down to, but I'm not sure why Dom0 is using 600mb of RAM.  Is
> > there a mini installation of CentOS that I can do that would use less RAM?
> >  I've already unchecked all the boxes when installing CentOS. I would like
> > Dom0 to be as small as possible, both due to RAM usage and from a security
> > perspective.
> I've not familiarized myself with xen yet, but have you considered
> VMware Server?  I haven't had any serious problems with it, and none
> at all since v1.0.5 came out (1.0.6 is the current one).  Works
> nicely, stays within its memory allocation, and top et al work as
> you'd expect them to.
> mhr

I evaluated VMware Server myself (v1.0.3) and at that time, Disk I/O was
pretty bad within a virtual machine. The only solution I found was XEN
with paravirtualization. Has there been any progress on that with later

For example: 

dd if=/dev/md5 of=/dev/null bs=1M count=1000 on bare metal gave 272 MB/s
same within VMware gave only 47,9 MB/s

I know that dd is not a benchmark - but for measuring sequential reads
within a system its fair enough for me.


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