From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: how can I copy files bigger than ~32 GB when using compress-force? Date: Mon, 04 Oct 2010 22:26:26 +0200 Message-ID: <4CAA3872.3080106@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed To: linux-btrfs@vger.kernel.org Return-path: List-ID: I'm trying to copy a ~220 GB file from a ext4 to btrfs filesystem with 336 GB free space on it. System is running 2.6.36-rc6. File size on a ext4 filesystem: # ls -l srv1-backup.qcow2 -rw-r--r-- 1 root root 219564146688 2010-09-26 21:56 srv1-backup.qcow2 Unfortunately it fails when only about 32 GB is copied (with compress-force mount option enabled). Copying to btrfs mount point stops, no reads or writes from any filesystem, after file copied to btrfs is around 32 GB: $ ls -l /mnt/btrfs/srv1-backup.qcow2 -rw-r--r-- 1 root root 32328482816 2010-10-04 21:49 /mnt/btrfs/srv1-backup.qcow2 This is 100% reproducible, when it gets to ~32 GB (varies by +/- 2 GB), cp can't be interrupted, killed and the only way to get this "fixed" seem to be rebooting the machine. _Sometimes_, cp quits after waiting for longer with "no space left". To reproduce: Let's create a btrfs filesystem: # mkfs.btrfs /dev/sdb4 WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL WARNING! - see http://btrfs.wiki.kernel.org before using fs created label (null) on /dev/sdb4 nodesize 4096 leafsize 4096 sectorsize 4096 size 335.72GB Btrfs Btrfs v0.19 # mount -o noatime,compress-force /dev/sdb4 /mnt/btrfs/ # df -h /mnt/btrfs Filesystem Size Used Avail Use% Mounted on /dev/sdb4 336G 56K 336G 1% /mnt/btrfs # cp -v srv1-backup.qcow2 /mnt/btrfs/ `srv1-backup.qcow2' -> `/mnt/btrfs/srv1-backup.qcow2' It always hands for me after copying ~32 GB, or quits with "no space left". -- Tomasz Chmielewski http://wpkg.org