From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chester Subject: Re: Set nodatacow per file? Date: Mon, 27 Feb 2012 16:10:50 -0600 Message-ID: References: <4F38B8F0.5020506@yahoo.com> <4F471E80.2040809@parallels.com> <4F4B8B02.9080303@parallels.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org To: dima Return-path: In-Reply-To: <4F4B8B02.9080303@parallels.com> List-ID: 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 vir= tio > disk without -z -C set and did not notice any difference in performan= ce at > all - Redhat 6.2 Minimal installs in 10 minutes in each case. The "ab= ysmal" > performance as it was some several months ago (like 10 minutes just f= or > virtual disk formatting) under the same conditions is no more at leas= t 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. > > best > ~dima > > > > On 02/24/2012 02:22 PM, dima wrote: >> >> On 02/13/2012 04:17 PM, Ralf-Peter Rohbeck wrote: >>> >>> Hello, >>> is it possible to set nodatacow on a per-file basis? I couldn't fin= d >>> anything. >>> If not, wouldn't that be a great feature to get around the performa= nce >>> issues with VM and database storage? Of course cloning should still >>> cause COW. >> >> >> Hello, >> Going back to the original question from Ralf I wanted to share my >> experience. >> >> Yesterday I set up KVM+qemu and set -z -C with David's 'fileflags' >> utility for the VM image file. >> I was very pleased with results - Redhat 6 Minimal installation was >> installed in 10 minutes whereas it was taking 'forever' the last tim= e I >> tried it some 4 months ago. Writes during installation were very >> moderate. Performance of VM is excellent. Installing some big packag= es >> with yum inside VM goes very quickly with the speed indistinguishabl= e >> from that of bare metal installs. >> >> I am not quite sure should this improvement be attributed to the noc= ow >> and nocompress flags or to the overall improvement of btrfs (I am on >> 3.3-rc4 kernel) but KVM is definitely more than usable on btrfs now. >> >> I am yet to test the install speed and performance without those fla= gs >> set. >> >> best >> ~dima >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrf= s" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs= " in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html