Re: Large sized guest taking for ever to boot...

[Alex Williamson <alex.williamson@redhat.com>]

On Fri, 2012-06-08 at 10:10 -0700, Chegu Vinod wrote:
> On 6/8/2012 9:46 AM, Alex Williamson wrote:
> > On Fri, 2012-06-08 at 16:29 +0000, Chegu Vinod wrote:
> >> Hello,
> >>
> >> I picked up a recent version of the qemu (1.0.92 with some fixes) and tried it
> >> on x86_64 server (with host and the guest running 3.4.1 kernel).
> 
> BTW, I observe the same thing if i were to use 1.1.50 version of the 
> qemu... not sure if this is really
> related to qemu...
> 
> >>
> >> While trying to boot a large guest (80 vcpus + 512GB) I observed that the guest
> >> took for ever to boot up...  ~1 hr or even more. [This wasn't the case when I
> >> was using RHEL 6.x related bits]
> > Was either case using device assignment?  Device assignment will map and
> > pin each page of guest memory before startup, which can be a noticeable
> > pause on smallish (<16GB) guests.  That should be linear scaling though
> > and if you're using qemu and not qemu-kvm, not related.  Thanks,
> 
> I don't have any device assignment at this point . Yes I am using qemu  
> (not qemu-kvm)...

Just to be safe, are you using --enable-kvm with qemu?

> The issue seems very basic... 'was earlier running RHEL6.3 RC1 on the 
> host and the guest and the host and the guest seemed to boot fine..

Note that RHEL is based on qemu-kvm.  Thanks,

Alex