[CentOS] Centos 5.2 and Xen

[Ruslan Sivak]

Luke S Crawford wrote:
> russ at vshift.com writes:
>   
>> If you only have 512mb of ram, there's almost no reason to virtualize. Windows needs a minimum of 128-512MB to run stable.  I highly suggest that you get more RAM - its very cheap these days.  
>>     
>
> seconded.  my standard server has 8G unbuffered ecc.  Newegg sells 
> 2x2Gb packs of unbuffered ECC kingston brand ddr2 for under $100.
>
> http://www.newegg.com/Product/Product.aspx?Item=N82E16820134312
>
> No reason, really, to not fill your motherboard with ram.  
>
>   
>> If you want to dedicate a box to virtualization, and won't be using more then 4GB of ram for your virtual machines - I highly recommend xenserver express.  Its free, but has much better performance then vmware.  
>>     
>
> the free (closed) xensource product is good... I also wanted to point out 
> the new gpl windows pv drivers:
>
> http://wiki.xensource.com/xenwiki/XenWindowsGplPv/
>
> you could use them with the standard open-source Xen, or even with the 
> Xen support distributed with CentOS 5, and avoid the ram limits all together.
> (well, there is a limit to the open-source xen, but it's ridiculous;  most
> of us won't hit it for several years, at least.)  
>
> still kinda beta, but something to watch.  
>
>
>   

Yea, I've been playing around with this.  The performance seems on par 
with the XenSource drivers, but like you said, it's pretty beta.  James 
has been great in fixing the bugs, but it's just not ready for 
production use right now.  Without using the GPLPV drivers, Xen is not 
ready for production use, the IO throughput sucks, and there is no 
graceful shutdown. 

If XenServer Express would only allow for 8GB, it would be perfect.  The 
administrative interface is really polished and fully featured (except 
things like migrations, which understandably come with the enterprise 
version). 

Once the GPLPV drivers mature a little bin and someone makes some decent 
admin tools for Xen, Xen will be ready for the enterprise.  I bet a 
company can make good money just developing and selling the admin tools 
for Xen.

Russ