P.S. I added another virtual disk to make it happy. The problem is that I cannot see anything critically close to be exhausted. So I have no reliable way of monitoring and predict when the problem appears.

Thanks
Peter


On Tue, Jul 28, 2015 at 9:54 AM, Peter Ross <petrosssit@gmail.com> wrote:
Russell Coker wrote:
Looks like you are running low on metadata space.  Run a balance to free a
> data chunk.

# btrfs balance /
ERROR: error during balancing '/' - No space left on device
There may be more info in syslog - try dmesg | tail
[root@m-admin03 ~]# dmesg | tail
..
[57720.728021] BTRFS info (device sda3): relocating block group 12582912 flags 1
[57721.462525] BTRFS info (device sda3): relocating block group 4194304 flags 4
[57722.195723] BTRFS info (device sda3): relocating block group 0 flags 2
[57723.302220] BTRFS info (device sda3): 14 enospc errors during balance

> The GPL vs BSD license debate has died down.  Most people who matter
> prefer GPL while most companies prefer BSD so they can take free
> software and make it non-free.

Well, I am a sysadmin and simply interested in technology that works.

Yes, Chris, CentOS7 is based on 3.10, a 2 years old kernel, but CentOS7 is a distribution I use now.

I happily used ZFS 2 years ago, and jails, and see nothing as pale imitations and "magic' in the system I am using now. Obviously we cannot even predict anymore when your filesystems are mounted, as the systemd/btrfs thread illustrates.

We muddle our way through, that's all. There is no beauty in it.

Regards
Peter


On Mon, Jul 27, 2015 at 10:54 PM, Russell Coker <russell@coker.com.au> wrote:
On Mon, 27 Jul 2015 06:00:40 PM Peter Ross wrote:
> On CentOS7 I get "No space left on device errors" just now..
>
> [root@m-admin03 ~]# btrfs scrub start /
> WARNING: failed to write the progress status file: No space left on device.
> Status recording disabled
> scrub started on /, fsid 25f5d19c-a4d3-4f28-9abb-699362765879 (pid=2833)
> [root@m-admin03 ~]# btrfs scrub status /
> scrub status for 25f5d19c-a4d3-4f28-9abb-699362765879
> no stats available

Some of the btrfs commands write a file to disk to track the status of things,
it's not unlike the way LVM and mdadm use files under /etc.  When there is no
space for a small file you have bigger problems than the filesystem not being
scrubbed.  So the first thing to do is to solve that.

> total bytes scrubbed: 0.00 with 0 errors
> [root@m-admin03 ~]# btrfs filesystem df /
> Data, single: total=5.97GiB, used=4.45GiB
> System, DUP: total=8.00MiB, used=16.00KiB
> System, single: total=4.00MiB, used=0.00
> Metadata, DUP: total=341.38MiB, used=242.31MiB
> Metadata, single: total=8.00MiB, used=0.00
> GlobalReserve, single: total=96.00MiB, used=0.00
>
> Sorry, I don't understand this..

Looks like you are running low on metadata space.  Run a balance to free a
data chunk.

> As for the licensing: I could not be more bored. ZFS has a life outside
> Oracle.

The GPL vs BSD license debate has died down.  Most people who matter prefer
GPL while most companies prefer BSD so they can take free software and make it
non-free.

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