Stability of Btrfs in Kernel 3.0

Stability of Btrfs in Kernel 3.0

[Maximilian Eschenbacher]

Greetings,

I am wondering about the stability of btrfs in this kernel version since
Negear ist selling those ReadyNAS with a buttload of features including
btrfs and linux kernel 3.0.

Is this a system one can use to keep backup? Do you have any suggestions
on what operations may be cause problems or how to keep btrfs happy and
running?

Best regards,

Maximilian Eschenbacher

Re: Stability of Btrfs in Kernel 3.0

[Martin Steigerwald]

Am Donnerstag, 4. Juni 2015, 14:54:48 schrieb Maximilian Eschenbacher:
> Greetings,
> 
> I am wondering about the stability of btrfs in this kernel version since
> Negear ist selling those ReadyNAS with a buttload of features including
> btrfs and linux kernel 3.0.
> 
> Is this a system one can use to keep backup? Do you have any suggestions
> on what operations may be cause problems or how to keep btrfs happy and
> running?

BTRFS and Kernel 3.0?

Unless its has a newer BTRFS version or at least critical fixed backported, I 
would run away from it.

Free space management in Kernel 3.0 still had issues that even with 2 GiB 
free the filesystem could report its full, while also denying to rm a file, 
delete a subvolume or do anything else to mitigate the situation. I have 
seen this on SLES 11 SP 3.

I suggest something newer. Really.

Or, if you still want to use it:

If you want to store 50 GiB, keep 50 GiB of space free, or at least 20-30 
GiB. I.e. have plenty of free space on the device. Do not fill up the 
filesystem.

Or well… use another filesystem on that device.

In addition meanwhile there will be a ton of other issues with such an old 
BTRFS fixed.

So until you can´t get a newer kernel for that device, I would not use it 
with BRFS.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7

Re: Stability of Btrfs in Kernel 3.0

[Maximilian Eschenbacher]

Hey Martin,

On 04/06/2015 15:55:49, Martin Steigerwald wrote:
>BTRFS and Kernel 3.0?
>
>Unless its has a newer BTRFS version or at least critical fixed
>backported, I would run away from it.
>
>Free space management in Kernel 3.0 still had issues that even with 2
>GiB free the filesystem could report its full, while also denying to rm
>a file, delete a subvolume or do anything else to mitigate the
>situation. I have seen this on SLES 11 SP 3.
>
>I suggest something newer. Really.
>
>Or, if you still want to use it:
>
>If you want to store 50 GiB, keep 50 GiB of space free, or at least
>20-30 GiB. I.e. have plenty of free space on the device. Do not fill up
>the filesystem.
>
>Or well… use another filesystem on that device.
>
>In addition meanwhile there will be a ton of other issues with such an
>old BTRFS fixed.
>
>So until you can´t get a newer kernel for that device, I would not use
>it with BRFS.

thanks for the quick and precise answer. I will find out whether Netgear
did some backporting for btrfs in their kernel and report back.

Unfortunately Netgear uses only btrfs (or zfs on some systems) and one
cannot select another fs like ext4 (which they supported on previous
systems).

Regards,

Max

Re: Stability of Btrfs in Kernel 3.0

[Justin Maggard]

Yes, ReadyNAS btrfs is a long way away from 3.0 btrfs.  And RN202/204
currently ship with a 3.12 kernel, and will be updated further soon.
There are also firmware versions currently available in beta for all
other hardware platforms using a much newer kernel, if you'd rather.
But anyway, here's a diffstat of the fs/btrfs directory:

 linux-3.0.101-netgear/fs/btrfs/Kconfig            |   40
 linux-3.0.101-netgear/fs/btrfs/Makefile           |   10
 linux-3.0.101-netgear/fs/btrfs/acl.c              |   36
 linux-3.0.101-netgear/fs/btrfs/async-thread.c     |  181
 linux-3.0.101-netgear/fs/btrfs/async-thread.h     |    8
 linux-3.0.101-netgear/fs/btrfs/backref.c          |only
 linux-3.0.101-netgear/fs/btrfs/backref.h          |only
 linux-3.0.101-netgear/fs/btrfs/btrfs_inode.h      |  126
 linux-3.0.101-netgear/fs/btrfs/check-integrity.c  |only
 linux-3.0.101-netgear/fs/btrfs/check-integrity.h  |only
 linux-3.0.101-netgear/fs/btrfs/compat.h           |   28
 linux-3.0.101-netgear/fs/btrfs/compression.c      |  108
 linux-3.0.101-netgear/fs/btrfs/compression.h      |    4
 linux-3.0.101-netgear/fs/btrfs/cslink.c           |only
 linux-3.0.101-netgear/fs/btrfs/cslink.h           |only
 linux-3.0.101-netgear/fs/btrfs/ctree.c            | 2943 ++++++++++---
 linux-3.0.101-netgear/fs/btrfs/ctree.h            | 1623 ++++++-
 linux-3.0.101-netgear/fs/btrfs/delayed-inode.c    |  596 +-
 linux-3.0.101-netgear/fs/btrfs/delayed-inode.h    |    8
 linux-3.0.101-netgear/fs/btrfs/delayed-ref.c      |  391 +
 linux-3.0.101-netgear/fs/btrfs/delayed-ref.h      |  113
 linux-3.0.101-netgear/fs/btrfs/dev-replace.c      |only
 linux-3.0.101-netgear/fs/btrfs/dev-replace.h      |only
 linux-3.0.101-netgear/fs/btrfs/dir-item.c         |  270 +
 linux-3.0.101-netgear/fs/btrfs/disk-io.c          | 2565 ++++++++----
 linux-3.0.101-netgear/fs/btrfs/disk-io.h          |   46
 linux-3.0.101-netgear/fs/btrfs/export.c           |    4
 linux-3.0.101-netgear/fs/btrfs/extent-tree.c      | 4106 +++++++++++++------
 linux-3.0.101-netgear/fs/btrfs/extent_io.c        | 2663 +++++++++---
 linux-3.0.101-netgear/fs/btrfs/extent_io.h        |  205
 linux-3.0.101-netgear/fs/btrfs/extent_map.c       |  231 -
 linux-3.0.101-netgear/fs/btrfs/extent_map.h       |   18
 linux-3.0.101-netgear/fs/btrfs/fiemap_physical.c  |only
 linux-3.0.101-netgear/fs/btrfs/file-item.c        |  227 -
 linux-3.0.101-netgear/fs/btrfs/file.c             | 1693 ++++++--
 linux-3.0.101-netgear/fs/btrfs/free-space-cache.c | 1756 ++++----
 linux-3.0.101-netgear/fs/btrfs/free-space-cache.h |    5
 linux-3.0.101-netgear/fs/btrfs/hash.h             |   10
 linux-3.0.101-netgear/fs/btrfs/inode-item.c       |  294 +
 linux-3.0.101-netgear/fs/btrfs/inode-map.c        |   60
 linux-3.0.101-netgear/fs/btrfs/inode.c            | 4642 ++++++++++++++--------
 linux-3.0.101-netgear/fs/btrfs/ioctl.c            | 2608 +++++++++---
 linux-3.0.101-netgear/fs/btrfs/ioctl.h            |  302 +
 linux-3.0.101-netgear/fs/btrfs/locking.c          |  350 -
 linux-3.0.101-netgear/fs/btrfs/locking.h          |   40
 linux-3.0.101-netgear/fs/btrfs/math.h             |only
 linux-3.0.101-netgear/fs/btrfs/ordered-data.c     |  441 +-
 linux-3.0.101-netgear/fs/btrfs/ordered-data.h     |   62
 linux-3.0.101-netgear/fs/btrfs/orphan.c           |    2
 linux-3.0.101-netgear/fs/btrfs/print-tree.c       |   26
 linux-3.0.101-netgear/fs/btrfs/print-tree.h       |    2
 linux-3.0.101-netgear/fs/btrfs/qgroup.c           |only
 linux-3.0.101-netgear/fs/btrfs/rcu-string.h       |only
 linux-3.0.101-netgear/fs/btrfs/reada.c            |only
 linux-3.0.101-netgear/fs/btrfs/relocation.c       |  405 +
 linux-3.0.101-netgear/fs/btrfs/root-tree.c        |  136
 linux-3.0.101-netgear/fs/btrfs/scrub.c            | 3188 ++++++++++++---
 linux-3.0.101-netgear/fs/btrfs/send.c             |only
 linux-3.0.101-netgear/fs/btrfs/send.h             |only
 linux-3.0.101-netgear/fs/btrfs/struct-funcs.c     |  183
 linux-3.0.101-netgear/fs/btrfs/super.c            | 1228 ++++-
 linux-3.0.101-netgear/fs/btrfs/transaction.c      | 1167 +++--
 linux-3.0.101-netgear/fs/btrfs/transaction.h      |   41
 linux-3.0.101-netgear/fs/btrfs/tree-defrag.c      |   19
 linux-3.0.101-netgear/fs/btrfs/tree-log.c         | 1500 +++++--
 linux-3.0.101-netgear/fs/btrfs/tree-log.h         |    5
 linux-3.0.101-netgear/fs/btrfs/ulist.c            |only
 linux-3.0.101-netgear/fs/btrfs/ulist.h            |only
 linux-3.0.101-netgear/fs/btrfs/volumes.c          | 3157 ++++++++++++--
 linux-3.0.101-netgear/fs/btrfs/volumes.h          |  172
 linux-3.0.101-netgear/fs/btrfs/xattr.c            |   94
 linux-3.0.101-netgear/fs/btrfs/zlib.c             |    8
 linux-3.0.101-orig/fs/btrfs/ref-cache.c           |only
 linux-3.0.101-orig/fs/btrfs/ref-cache.h           |only
 74 files changed, 29498 insertions(+), 10648 deletions(-)

-Justin

On Thu, Jun 4, 2015 at 8:33 AM, Maximilian Eschenbacher
<maximilian@eschenbacher.email> wrote:
> Hey Martin,
>
> On 04/06/2015 15:55:49, Martin Steigerwald wrote:
>>
>> BTRFS and Kernel 3.0?
>>
>> Unless its has a newer BTRFS version or at least critical fixed
>> backported, I would run away from it.
>>
>> Free space management in Kernel 3.0 still had issues that even with 2
>> GiB free the filesystem could report its full, while also denying to rm
>> a file, delete a subvolume or do anything else to mitigate the
>> situation. I have seen this on SLES 11 SP 3.
>>
>> I suggest something newer. Really.
>>
>> Or, if you still want to use it:
>>
>> If you want to store 50 GiB, keep 50 GiB of space free, or at least
>> 20-30 GiB. I.e. have plenty of free space on the device. Do not fill up
>> the filesystem.
>>
>> Or well… use another filesystem on that device.
>>
>> In addition meanwhile there will be a ton of other issues with such an
>> old BTRFS fixed.
>>
>> So until you can´t get a newer kernel for that device, I would not use
>> it with BRFS.
>
>
> thanks for the quick and precise answer. I will find out whether Netgear
> did some backporting for btrfs in their kernel and report back.
>
> Unfortunately Netgear uses only btrfs (or zfs on some systems) and one
> cannot select another fs like ext4 (which they supported on previous
> systems).
>
> Regards,
>
> Max
>
> --
> 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