qcow2 format state in Lucid

[Imre Gergely]

On 03/22/2010 08:39 PM, Nikolai K. Bochev wrote:
> 
> Hello list,
> 
> I am quite curious about the state of qcow2 format in Lucid. As i
> recently discovered, when running a KVM machine with a qcow2 disk , i
> get a great performance hit under karmic. Seems that not only disk
> performance is decreased ( copying with 2 Mb/sec from the host to the
> guest and with around the same from the network to the guest ), but it
> hits the cpu on the guest pretty hard and the machine ( guest ) can
> become quite unstable. I know this is more of a  KVM/QEMU question, but
> i was wondering if anyone played around with Lucid already and with that
> part in particular. I have quite a few virtual hosts with lots of guests
> on them running on production environments and i want to know if i
> should just switch to raw format or wait until Lucid comes out and keep
> the qcow2 format of the disks.

I did notice some strange slowdowns, but not like this. I have a Karmic
host and tried to install the (then) latest lucid from a nightly iso
alternate iso. It was extremely slow, it installed the base system in
like an hour or so, it just stood there, apparently without doing
anything (for example at kernel install).
I've installed a couple of guests, none of which were this slow.

I didn't do any further investigation because I needed that guest right
away, so I just installed a Karmic and upgraded to Lucid, was a lot
faster ;)

Probably isn't related to this, but I just remembered. I'll try to
reproduce it when I get home.

-- 
Imre Gergely
Yahoo!: gergelyimre | ICQ#: 101510959
MSN: gergely_imre | GoogleTalk: gergelyimre
gpg --keyserver subkeys.pgp.net --recv-keys 0x34525305