From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:60562 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbaIIWXv (ORCPT ); Tue, 9 Sep 2014 18:23:51 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XRTpE-0007E2-At for linux-btrfs@vger.kernel.org; Wed, 10 Sep 2014 00:23:48 +0200 Received: from pd953e39c.dip0.t-ipconnect.de ([217.83.227.156]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Sep 2014 00:23:48 +0200 Received: from holger.hoffstaette by pd953e39c.dip0.t-ipconnect.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Sep 2014 00:23:48 +0200 To: linux-btrfs@vger.kernel.org From: Holger =?iso-8859-1?q?Hoffst=E4tte?= Subject: Re: ENOSPC on mostly empty file system Date: Tue, 9 Sep 2014 22:23:33 +0000 (UTC) Message-ID: References: <3150960.nnNb4J6vhp@wuerfel> <4255785.FLXNWijYCD@wuerfel> <10095560.XRujO0W0CE@wuerfel> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, 09 Sep 2014 23:49:10 +0200, Arnd Bergmann wrote: > Label: none uuid: 1d88cccb-3d0e-42d9-8252-a226dc5c2e47 > Total devices 1 FS bytes used 8.79GB > devid 1 size 67.14GB used 67.14GB path /dev/sdc6 ^^^^^^^^^^^^^^^^^^^^ *ding ding ding* The term "used" is confusing here and really should be called "allocated", since it's more than the number of actually used bytes. Note that df shows that you "have" ~66GB data and ~1GB metadata (giving approx. ~67GB), despite the fact that of those 65GB data allocated only ~8GB are actually used. However all these reserved data chunks are preventing the metadata space from expanding, which is pretty full: Metadata, DUP: total=1.00GB, used=799.54MB Here "total" also should be "allocated/reserved" and is 1GB, but btrfs feels it's necessary to allocate a new metadata chunk (which would also increase "total") and fails. Running balance with -dusage=x will garbage-collect the reserved but mostly-empty data chunks with "up to x" percent actual usage. -h