From mboxrd@z Thu Jan 1 00:00:00 1970 From: dima Subject: Re: Set nodatacow per file? Date: Fri, 2 Mar 2012 12:28:19 +0900 Message-ID: <4F503E53.6070309@parallels.com> References: <4F38B8F0.5020506@yahoo.com> <4F471E80.2040809@parallels.com> <4F4B8B02.9080303@parallels.com> <4F4C251E.7040601@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed To: Return-path: In-Reply-To: <4F4C251E.7040601@parallels.com> List-ID: On 02/28/2012 09:51 AM, dima wrote: > On 02/28/2012 07:10 AM, Chester wrote: >> On Mon, Feb 27, 2012 at 7:54 AM, dima wrote: >>> Hello, >>> >>> Since several people asked to post the results, here they are. >>> I tried raw virtio disk with and without -z -C set and also qcow2 virtio >>> disk without -z -C set and did not notice any difference in >>> performance at >>> all - Redhat 6.2 Minimal installs in 10 minutes in each case. The >>> "abysmal" >>> performance as it was some several months ago (like 10 minutes just for >>> virtual disk formatting) under the same conditions is no more at >>> least on >>> 3.3.0-rc5. >> >> Just to make sure, this is a _new_ virtual disk right? I can barely >> contain my excitement right now. This is amazing progress. > > Yes, it is a newly created virtual disk. By the way, one thing that > slipped out from my message - in case of raw I did pre-allocation of the > entire image, but in case of qcow2 I unchecked this box in virt-manager > and the disk was "growing" as the system was installing. Nevertheless I > did not notice performance degradation during the install. But still Virtualbox is faster. It installs Redhat 6 Minimal in just about 5 minutes. I observe that yum installations work faster. WindowsXP install under KVM was a hell lasting for about 3 hours and the performance is awful with host HD indicator flashing all the time. There was no change whatsoever whether the image was with +C +z or not. On Virtualbox WinXP install completed in about 25 minutes and the performance is excellent even w/o guest additions applied. I wonder why such a big difference.