Hi Josef,

same again with chris next branch:

ERROR: error during balancing '/vmbackup/': No space left on device
There may be more info in syslog - try dmesg | tail
Dumping filters: flags 0x7, state 0x0, force is off
  DATA (flags 0x2): balancing, usage=5
  METADATA (flags 0x2): balancing, usage=5
  SYSTEM (flags 0x2): balancing, usage=5

dmesg:
[203784.411189] BTRFS info (device dm-0): 114 enospc errors during balance

uname -r 4.7.0-rc6-29043-g8b8b08c

Greets,
Stefan

Am 08.08.2016 um 08:17 schrieb Stefan Priebe - Profihost AG:

Am 04.08.2016 um 13:40 schrieb Stefan Priebe - Profihost AG:

quoted

Am 29.07.2016 um 23:03 schrieb Josef Bacik:

quoted

On 07/29/2016 03:14 PM, Omar Sandoval wrote:

quoted

On Fri, Jul 29, 2016 at 12:11:53PM -0700, Omar Sandoval wrote:

quoted

On Fri, Jul 29, 2016 at 08:40:26PM +0200, Stefan Priebe - Profihost
AG wrote:

quoted

Dear list,

i'm seeing btrfs no space messages frequently on big filesystems (>
30TB).

In all cases i'm getting a trace like this one a space_info warning.
(since commit [1]). Could someone please be so kind and help me
debugging / fixing this bug? I'm using space_cache=v2 on all those
systems.

Hm, so I think this indicates a bug in space accounting somewhere else
rather than the free space tree itself. I haven't debugged one of these
issues before, I'll see if I can reproduce it. Cc'ing Josef, too.

I should've asked, what sort of filesystem activity triggers this?

Chris just fixed this I think, try his next branch from his git tree

git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git

Thanks now running a 4.4 with those patches backported. If that still
shows an error i will try that vanilla tree.

OK this didn't work. I'll start / try using the linux-btrfs next branch
and look if this helps.

Greets,
Stefan

quoted

Thanks!

Stefan

quoted

and see if it still happens.  Thanks,

Josef