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 13:12:37 +0200 Message-ID: <4CB442A5.20406@wpkg.org> References: <4CAA4A34.80701@wpkg.org> <20101004222837.GD9759@think> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Chris Mason , linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <20101004222837.GD9759@think> List-ID: 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. [103678.068434] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [103678.068439] qemu-kvm D 00000001062a02ba 0 18722 18607 0x00000000 [103678.068446] ffff88008d80bb38 0000000000000082 ffff880000000000 00000000000148c0 [103678.068453] ffff88008725db00 00000000000148c0 ffff88008d80bfd8 00000000000148c0 [103678.068459] ffff88008d80a000 00000000000148c0 ffff88008725dea8 00000000000148c0 [103678.068466] Call Trace: [103678.068490] [] btrfs_start_ordered_extent+0x75/0xc0 [btrfs] [103678.068499] [] ? autoremove_wake_function+0x0/0x40 [103678.068517] [] btrfs_wait_ordered_range+0xc1/0x160 [btrfs] [103678.068535] [] btrfs_file_aio_write+0x542/0x9a0 [btrfs] [103678.068542] [] ? futex_wait_queue_me+0xc2/0x100 [103678.068549] [] ? hrtimer_cancel+0x22/0x30 [103678.068568] [] ? btrfs_file_aio_write+0x0/0x9a0 [btrfs] [103678.068576] [] do_sync_readv_writev+0xd3/0x110 [103678.068583] [] ? do_futex+0x109/0xb00 [103678.068590] [] ? security_file_permission+0x29/0xa0 [103678.068597] [] do_readv_writev+0xd4/0x1f0 [103678.068603] [] ? kill_pid_info+0x3f/0x60 [103678.068610] [] vfs_writev+0x48/0x60 [103678.068615] [] sys_pwritev+0xa2/0xc0 [103678.068623] [] system_call_fastpath+0x16/0x1b -- Tomasz Chmielewski http://wpkg.org