From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: how can I copy files bigger than ~32 GB when using compress-force? Date: Tue, 12 Oct 2010 17:01:11 +0200 Message-ID: <4CB47837.6090407@wpkg.org> References: <4CAA4A34.80701@wpkg.org> <20101004222837.GD9759@think> <4CB442A5.20406@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed To: Chris Mason , linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <4CB442A5.20406@wpkg.org> List-ID: On 12.10.2010 13:12, Tomasz Chmielewski wrote: > On 05.10.2010 00:28, Chris Mason wrote: > >>>> Does it happen with any 32gb file that doesn't compress well? >>> >>> The 220 GB qcow2 file was basically uncompressible (backuppc archive >>> full of bzip2-compressed files). >> >> Ok, I think I know what is happening here, they all lead to the same >> chunk of code. I'll be able to reproduce this locally. > > FYI, qemu/kvm doesn't seem to like its files located on btrfs mounted with compress-force. > > I have a filesystem mounted with noatime,compress-force, where I created a 100GB sparse file. > There, I wanted to install a Linux distribution - however, the whole qemu-kvm process hanged with these entries being repeated over and over. > It's not possible to kill the qemu-kvm process (even with kill -9) etc. > > > [103678.068429] INFO: task qemu-kvm:18722 blocked for more than 120 seconds. Hmm, I see it blocks infinitely like this whether qemu-kvm tries to access a sparse file mounted with compress, compress-force, or no compression at all. Also hangs with non-sparse files mounted without compression (didn't try with compression). So must be some other bug. And, I see occasional: bad ordered accounting left 4096 size 12288 when it happens. -- Tomasz Chmielewski http://wpkg.org