Re: Again, no space left on device while rebalancing and recipe doesnt work

[Marc Haber <mh+linux-btrfs@zugschlus.de>]

On Sun, Mar 06, 2016 at 01:27:10PM -0700, Chris Murphy wrote:
> Marc said it was created maybe 2 years ago and doesn't remember what
> version of the tools were used. Between it being two years ago and
> also being Debian, for all we know it could've been 0.19. *shrug*

You are mixing up Debian unstable and Debian stable *snort*. You're
lucky that I'm not on RHEL 6[1].

> On the one hand, the practical advice is to just blow it away and use
> everything current, go back to the same workload including thousands
> of snapshots, and see if this balance problem is reproducible. That's
> pretty clearly a bug.

To have the same thing happen in half a year again? That's not why I
converted to a snapshottable file system.

> On the other hand, we're approaching the state with Btrfs where the
> problems we're seeing are at least as much about aging file systems,
> because the stability is permitting file systems to get older.

And this is really something to be proud of? I mean, this is a file
system that is part of the vanilla linux kernel, not marked as
experimental or something, and you're still concerned about file
systems that were made a year ago? This is a new experience for me.

>  As they get older though, the issues get more non-deterministic. So
>  it's an interesting bug from that perspective, the current kernel
>  code ought to be able to contend with this (as in, the user is right
>  to expect the code to deal with this scenario, and if it doesn't it's
>  a bug; not that I expect today's code to actually do this).

Kernel 4.4.4 as of the day before yesterday, thanks for considering.

> So if it were me, I'd gather all possible data, including complete,
> not trimmed, logs.

So you seriously want all messages like
Mar  7 09:25:23 fan systemd[1]: Started http per-connection Server, forwarding to 3142 ([2a01:238:4071:328d:5054:ff:fea9:6807]:41060).
Mar  7 09:25:23 fan named[3000]: client 2a01:238:4071:328d:5054:ff:fea9:6807#59920 (debian.debian.zugschlus.de): query: debian.debian.zugschlus.de IN AAAA + (fec0:0:0:ffff::1)
Mar  7 09:21:34 fan dhcpd[2468]: DHCPREQUEST for 192.168.182.29 from 54:04:a6:82:21:00 via eth0: unknown lease 192.168.182.29.
Mar  7 09:17:01 fan CRON[19474]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Mar  7 09:18:06 fan systemd[1]: Started Session c101 of user mh.
Mar  7 08:21:40 fan smartd[1956]: Device: /dev/sdb [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 31 to 30

I _can_ swamp the bug report literally with gigabytes of logs, but is
that really what you want? If it is not, please state what you mean by
"not trimmed" as I only removed those clutter messages from the logs I
sent.

Greetings
Marc

[1] Does RHEL 6 have btrfs in the first place?

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