[CentOS] Centos 5.2 and Xen

Ruslan Sivak russ at vshift.com
Sun Jun 15 21:41:33 UTC 2008

Robert - elists wrote:
> I have an 8 gig dram server I am playing with Xen on in centos 5.1 on right
> now.
> Are you telling us that Xen on centos 5.1 only uses 4 Gig Dram?
> Or will it allow all 8 Gig to be used if setup correctly between main dom
> and virt doms
>  - rh

I think if you're on an x64 bit platform you can use up to 8GB of ram 
for dom0 (well you need to leave enough for dom0, mine takes up about 
600mb after a clean install, and if you allocate too much to domU, the 
server goes down - hard).

What I was talking about is XenServer - the commercial product based on 
Xen now owned by citrix.  They have a bare metal installer that installs 
a version of CentOS 5 and their version of Xen in about 10 minutes, and 
has a very nice windows based administrative console.  Their free 
version XenServer Express only allows DomU to use up to 4GB of RAM 
collectivelly, and I believe only 4 VMs total.  They also have fairly 
nice paravirtualized drivers for windows (although James' GPLPV drivers 
are catching up to them).

I think I will run XenServer at home where I have a box with only 4GB of 
RAM, but for work, I'm probably going to go with CentOS 5.2 and Xen 3.2, 
since XenServer is too limiting, and I don't think it's worth shelling 
out $1k per box to get use of the other 3.5GB of RAM.


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