From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.com header.i=quwenruo.btrfs@gmx.com header.b="sOxVDIxL" Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6AB0B0 for ; Mon, 11 Dec 2023 20:13:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.com; s=s31663417; t=1702354412; x=1702959212; i=quwenruo.btrfs@gmx.com; bh=p1oJ8/ru5mY7ONinjoLwumBDEMEROQcqQJw7lhMEkjU=; h=X-UI-Sender-Class:Date:Subject:To:References:From:In-Reply-To; b=sOxVDIxL8uJfz4zjQpz2rMKp4uv56EJoGtKGDVROpH0lq80LP0r1c+WBec2m3wOx /riX3pvCF6Db35ItaksjLhxaWdHDI11H8ZoAOvq3tjAdD2H0Q/oR1Vj5c4oO0x3R3 /cHsMqv3wva6gDoOJLWnaZUkSxGPZkfJhUfArnqNyWIkf7OItsYvZPP/g+k7oHVFk 7gGyafaiq5KfxG9HBRhctKe6cIj8Ligr/UolLKidBCXOjYHB2lCNCnL/VEiNl/K7n swm7q9wNfWRxHyb29mJsZDCUKRa5YBv2Ff2BcEZ1tRxxOsQgZK07I7EKYYGslYf/7 HjNXneVP4RLV0cteSw== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [172.16.0.153] ([193.115.79.20]) by mail.gmx.net (mrgmx105 [212.227.17.174]) with ESMTPSA (Nemesis) id 1ML9yc-1qugm10zLu-00IH9U; Tue, 12 Dec 2023 05:13:32 +0100 Message-ID: <8a9b6743-37e6-4a71-9423-6ce5169959ac@gmx.com> Date: Tue, 12 Dec 2023 14:43:27 +1030 Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: btrfs thinks fs is full, though 11GB should be still free Content-Language: en-US To: Christoph Anton Mitterer , linux-btrfs@vger.kernel.org References: <0f4a5a08fe9c4a6fe1bfcb0785691a7532abb958.camel@scientia.org> <253c6b4e-2b33-4892-8d6f-c0f783732cb6@gmx.com> <95692519c19990e9993d5a93985aab854289632a.camel@scientia.org> <656b69f7-d897-4e9d-babe-39727b8e3433@gmx.com> <3cfc3cdf-e6f2-400e-ac12-5ddb2840954d@gmx.com> <2d5838efc179a557b41c84e9ca9a608be6a159e8.camel@scientia.org> <9ce30564e238d1be0deafb8cab8968f800a8deaa.camel@scientia.org> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; keydata= xsBNBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAHNIlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT7CwJQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCY00iVQUJDToH pgAKCRDCPZHzoSX+qNKACACkjDLzCvcFuDlgqCiS4ajHAo6twGra3uGgY2klo3S4JespWifr BLPPak74oOShqNZ8yWzB1Bkz1u93Ifx3c3H0r2vLWrImoP5eQdymVqMWmDAq+sV1Koyt8gXQ XPD2jQCrfR9nUuV1F3Z4Lgo+6I5LjuXBVEayFdz/VYK63+YLEAlSowCF72Lkz06TmaI0XMyj jgRNGM2MRgfxbprCcsgUypaDfmhY2nrhIzPUICURfp9t/65+/PLlV4nYs+DtSwPyNjkPX72+ LdyIdY+BqS8cZbPG5spCyJIlZonADojLDYQq4QnufARU51zyVjzTXMg5gAttDZwTH+8LbNI4 mm2YzsBNBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAHCwHwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCY00ibgUJDToHvwAK CRDCPZHzoSX+qK6vB/9yyZlsS+ijtsvwYDjGA2WhVhN07Xa5SBBvGCAycyGGzSMkOJcOtUUf tD+ADyrLbLuVSfRN1ke738UojphwkSFj4t9scG5A+U8GgOZtrlYOsY2+cG3R5vjoXUgXMP37 INfWh0KbJodf0G48xouesn08cbfUdlphSMXujCA8y5TcNyRuNv2q5Nizl8sKhUZzh4BascoK DChBuznBsucCTAGrwPgG4/ul6HnWE8DipMKvkV9ob1xJS2W4WJRPp6QdVrBWJ9cCdtpR6GbL iQi22uZXoSPv/0oUrGU+U5X4IvdnvT+8viPzszL5wXswJZfqfy8tmHM85yjObVdIG6AlnrrD In-Reply-To: <9ce30564e238d1be0deafb8cab8968f800a8deaa.camel@scientia.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:ARaz57s0FKsm9gts4VWVs1zPTBhOlEU29Maj/kgv9kuMVO474mJ Q7gsSV+GwhaZlqOD78mmLmwRaOp+YQpT1C3ZsmEVn/zV8rFFuOrZPYaGx19hUD8pmX2fpqP T+lZ6G3okndtSiOp8tiMfPR6+t1LbCRcmzxREm2JhAxg9OOWx9kYsNK3rH56iE7XlRSibTi 3qKA6Sg0lC0RiR21/5XFQ== UI-OutboundReport: notjunk:1;M01:P0:LhtgqrnzAOU=;jAkDZUAgkKOARiOD1hRIME07jd4 OFTUIDU+S9AQa3pWpoC8ln09EnKqTkyFv4/lC8a2jOwbVpKtqb2KmBaDOx33QhLs7/wIniqeB w8VBAGGAmKi6nUnudCDjoAU2AmpYxy5DrvsLJLUPFFdPSw3jIjN2JY/SvzXPdMnz43vfvN7HF fau89b6wY+S4yFLwqVx023L0INF6PAQYOF//4C/RqqpW3RoMkg7Ygvwo7sHGaUvA1lH/zVHxI bj/u0KFH/0HPCPzz20ektRysAhnTKIZzaT3iwA91RseF6FeNvddmgBH9/WAtIf7Ttx31Knq/j Anld82a/TSTqGRsrb/MtsWoCHlz61b2WjuRThc/z+anQvHrKPhZ8sPCVjBwbWbiyV/bbV/0tb RdhEWDq73mgOK+fSpyCKGio2PMW4VbVGd2Ft9Ha3ckroXjW40ynq/0uEzNcC6djH2Wj5zNHV9 REh3l4oBJbSGabMpnhaCwIkbM500wbqHFlXnsHaEj/4vNEnqXyNOAy5f5Ev6Botn8I397YQ8I ITWltxzRjf+TD3W92wPDkpjyyoNTGkycwNG1HxVkN8yONX88G3nR2HePyL908wnXvR8pYMb6t avl7BDHujYRa0q8Os96+VkzKGvctgegZK2Wkx5vuoB5kgR2b6grTBngIk/TIRXAAouY9AGQvX RLeTqmdRJY0nAqueWnbtTGliOhUYckNauCDxSvhbzVaIwV12fOGKtW4ISNqFHcaqn3d7nciJ4 KkH+9e3ZhN1Xeotzzqx5URWIyW3rVk2p3isAF4tnUg65LXTCZfrHBth6vj5b2AceXCaBvHq/x TUlyNCm5R3iTPMuhqM8VGdD9OhLUKIht8iugHEPY0U7bSMIi4A6UzOb+8cWP+v4BOgY956tUI clhhGfhK9aLfUn1ee91bCenKDpNrybTs+/WdrVmNqDyN1/PJJSvj/s9wrZfOZSHBePlGF6sL0 Dqbw4Q== On 2023/12/12 14:10, Christoph Anton Mitterer wrote: > I just noticed that others have already had that problem with > Prometheus: > https://github.com/prometheus/prometheus/issues/9107 > > Some users there wondered whether the issue could be caused by too > aggressive preallocation via `fallocate`. > > Do you think that would be something that could also cause the wasted > space? > Well, preallocated inodes (any inodes with any preallocated extents during its lifespan, it's a btrfs specific flag, won't be cleared until the inode is evicted), would only lead to btrfs to try NOCOW first, then fallback to COW if NOCOW failed. (Missing the compression path). It's not a direct cause to the problem. The direct cause is frequent fsync()/sync() with overwrites. Btrfs is really relying on merging the writes between transactions, if fsync()/sync() is called too frequently (like some data base) and the program is doing overwrites, this is exactly what you would have. IIRC we can set the AUTODEFRAG for an directory? Thanks, Qu > > Thanks, > Chris. >