[Fedora-xen] Kickstart slowness with virt-install

[Daniel P. Berrange]

On Wed, Mar 07, 2007 at 01:50:43PM -0800, Hanks, Dan wrote:
> Hi folks,
> 
>  
> 
> I've been able to kickstart a number of VMs using the virt-install tool,
> and so far have had pretty good success. One aspect of these installs
> has me a bit concerned, though. In most cases, anytime the kickstart
> needs to do intensive disk activity (such as formatting partitions, or
> installing all the rpms) there are noticible hangs, which I'm guessing
> come from some kind of IO wait. The result is that a kickstart which
> should take < 10 minutes ends up taking a half-hour or so. 

What kind of virtual disk image are you using for the guest ? A partition
or a file - if the latter is it sparse, or non-sparse. Basically sparse
files will be horribly slow because every time the host OS has to extend
the sparse file to allocate real blocks it needs to do a journal sync on
the host FS. This destroys performance of I/O from the guest until the
sparse file is fully-allocated. 

Regards,
Dan.
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