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

From: Chegu Vinod <chegu_vinod@hp.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
Subject: Re: Large sized guest taking for ever to boot...
Date: Fri, 08 Jun 2012 10:57:13 -0700	[thread overview]
Message-ID: <4FD23CF9.5000203@hp.com> (raw)
In-Reply-To: <1339177340.26976.111.camel@ul30vt>

On 6/8/2012 10:42 AM, Alex Williamson wrote:
> 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?

Yes...

-----

/etc/qemu-ifup tap0

/usr/local/bin/qemu-system-x86_64 -enable-kvm \

-cpu 
Westmere,+rdtscp,+pdpe1gb,+dca,+pdcm,+xtpr,+tm2,+est,+smx,+vmx,+ds_cpl,+monitor,+dtes64,+pclmuldq,+pbe,+tm,+ht,+s
s,+acpi,+ds,+vme \
-m 524288 -smp 80,sockets=80,cores=1,threads=1 \
-name vm1 \
-chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/vm1.monitor,server,nowait \
-drive 
file=/dev/libvirt_lvm/vm.img,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native 
\
-device 
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 
\
-monitor stdio \
-net nic,macaddr=52:54:00:71:01:01 \
-net tap,ifname=tap0,script=no,downscript=no \
-vnc :4

/etc/qemu-ifdown tap0

----

>> 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,

Yep..knew that :)

I was using upstream qemu-kvm and was encouraged to move away from 
it...to qemu.

Vinod

>
> Alex
>