kernel-PAE or xen or both?

[Konstantin Svist]

Maurizio Rottin wrote:
> HI all,
> i have a dom0 with 5GB of ram.
>
> i'm using kernel-xen both in dom0 and in domU's
>
> i'm running 4 virtual machines, but at some point the last created (or
> the one with the higest id) get crashed by something that i can't find
> out.
>
> No logs, but a mere
> [2008-03-05 11:28:08 xend.XendDomainInfo 3625] WARNING
> (XendDomainInfo:923) Domain has crashed: name=php01 id=369.
> [2008-03-05 11:28:09 xend.XendDomainInfo 3625] DEBUG
> (XendDomainInfo:1566) XendDomainInfo.destroyDomain(369)
> [2008-03-05 11:28:09 xend.XendDomainInfo 3625] DEBUG
> (XendDomainInfo:200) XendDomainInfo.create(['domain',[cut]
> in  /var/log/xen/xend.log
>
> Then i'm wandering if the problem can be memory usage, since to use
> more that 4GB i should use kernel_PAE instead.
> Maybe, if kernel-xen is not compiled against PAE, the server does not
> know how to use the last GB...just supposing...
> But can i have kernel-xen combined with PAE?!? i don't know...
>
> Anyone know if my setup is wrong?
>
>   

PAE is a clever hack in 32-bit system to allow it to address more than 
4GB of memory. Problem is, you can't address it all at once, you need to 
use it in smaller chunks. Maybe your virtual machine crosses that 
boundary.. or maybe there's a bug in Xen :)
The proper way to be able to use your 5GB is to install a 64-bit version 
of the OS. I highly recommend it unless it's a general-use workstation.