OpenSuSE 13.2: do not use BTRFS as rootfs

OpenSuSE 13.2 comes with BTRFS chosen as your default rootfs, replacing the old trusted ext4. Unfortunately the kernel version it ships with contains a known flaw which breaks some software using preallocated files and mmap() on them. Known issues have been reported for rtorrent (failed synchronization) and KDE (plasma-desktop crashes and could not be restarted even from terminal until reboot). Therefore please use ext4 filesystem for your root fs.

If you already used btrfs, you have two choices:

– Upgrade your kernel to at least 3.17.2 which would allegedly fix this issue. OpenSuSE offers those kernels in this repository. Unfortunately this may break some 3rd party components such as NVidia proprietary drivers.

– Downgrade your filesystem to ext4. The latter could be done as following:

  1. Boot from the rescue CD (you can use OpenSuSE 13.2 installation CD), mount the root file system and copy (cp -ax) its content to another disk with ext4 or other Linux root-compatible FS (not FAT/NTFS);
  2. Umount the root file system, and run mkfs.ext4 on it. Then mount it again as newroot, and copy (cp -ax) the files back.
  3. Run blkid and find out the new UUID for your root partition. Edit newroot/etc/fstab, and replace the UUID in the line mounting rootfs; replace btrfs by ext4 too.
  4. Chroot into it: mount /proc newroot/proc -o bind; mount /devc newroot/dev -o bind; mount /sys newroot/sys -o bind; chroot newroot
  5. Edit /etc/sysconfig/storage and set your rootfs as ext4: DEFAULT_FS=”ext4″
  6. Reinstall grub (if you forgot, you’ll get grub rescue shell at boot) by running grub2-install. Yast-bootloader does not install it properly.
  7. Reboot and enjoy.
This entry was posted in Uncategorized.

3 Responses to OpenSuSE 13.2: do not use BTRFS as rootfs

  1. nick[0] says:

    George, I’d like to keep my eye on the progress towards fixing these issues in linux-3.16.x, since they affect both OpenSUSE 12.3 and Debian Jessie. Could you please post links to the relevant bug reports? I’ve read that linux-3.17.x brings its own set of btrfs issues. eg:
    https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg38039.html
    https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg38049.html
    http://thr3ads.net/btrfs-devel/2014/11/2802524-corrupt-leaf-on-kernel-3.17.2-w-btrfs-progs-3.17

  2. roeland says:

    what is the opensuse bugzilla reference?

    What of the problems are already backported in the kernel? Do we know that?

  3. E B says:

    I was scratching my head helpless over this one. While freshly installing from the DVD, I merely flipped the installation filesystem from btfrs to ext4 and this fixed it for me. Thanks man.

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