From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from host6.manage-it-for.me (host6.manage-it-for.me [88.99.208.185]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B245E26980B for ; Sat, 30 Aug 2025 11:29:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=88.99.208.185 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756553386; cv=none; b=Vr0d2U/FDSPJbQFOPnxNjH/pRUW2Jd6JbACIIBuXMOvxRe01Au93mefks/DF2qlfE+rd8vWxAL2XYo4/GquqFu3ZhGYyxRHTFDKGZgrdigt2BtV2W7HQApaY8xK0lXSeFl0/63AulQTcik67+jLrOMI5ROGnr/1PnuncqTGsUrI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756553386; c=relaxed/simple; bh=CImg/PEcvgX0SzR6YQ0ybMzfQ4wu7zamQ8tSYeQ8ons=; h=From:To:MIME-Version:Date:Subject:Message-ID:Content-Type; b=CbOo2oN6Ak43SxA+jHQs/thEmzsh7KVSLWlGUy+f9wwbOt55jCm4LaAPqrb23s8qH9zjv3W6sLS5nye27SLv3pCB1MGKasQeGg/K240+M8nPJPbf0vbGTVGolyYF+KIZObD4Sx0pEH5w0VUVomC4pTEJSvuN+qswTRWNWhg1/7Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=maltris.org; spf=pass smtp.mailfrom=maltris.org; dkim=pass (2048-bit key) header.d=maltris.org header.i=@maltris.org header.b=aD/6LoNY; arc=none smtp.client-ip=88.99.208.185 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=maltris.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=maltris.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=maltris.org header.i=@maltris.org header.b="aD/6LoNY" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id 027AFC03D0 for ; Sat, 30 Aug 2025 13:29:42 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=maltris.org; s=dkim; t=1756553383; h=from:subject:date:message-id:to:mime-version:content-type: content-transfer-encoding; bh=CImg/PEcvgX0SzR6YQ0ybMzfQ4wu7zamQ8tSYeQ8ons=; b=aD/6LoNYf9StoIVTzDxirG7Ylf8NKJLGu+Nl9OSNAKQXu923vnIr+xozC5DQTiqSd7QSXU Xh3EHzmoXjhgiuMLBsoJQZi+dWW3VcqKBbmY2VmQ5pMr8yYb2Ytpgw+PCLW5AVNxFyFHgR rMk189c1xM8KnoO4wBsr6We4tXCYbu+2ErUWYlDG1s7m4OBm1jGe3R/WeDPyjGORe7n6fK RIaaifp0PFtshb5wvguT33Kt+5SwlE0nbuQ0LAcSu9O5YVf7iw4/i17yBldv/1yAw8/hmz 1DbVLVCEyC/wb+iaLRV2axjcMyREGb/+5L8cbpYsFv8COoYiq8a5hJ6PzaCocA== From: "Malte Schmidt" To: linux-ext4@vger.kernel.org User-Agent: SOGoMail 5.12.0 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Sat, 30 Aug 2025 13:29:42 +0200 Subject: =?utf-8?q?debugfs=2C?==?utf-8?q?_e2fsck=2C?= dumpe2fs on corrupted ~11 TB partition - all tools filling 16 GB of memory until getting ended Message-ID: <6b0f6-68b2e080-9-1e084900@214889527> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hello, I am currently dealing with a corrupted ext4 filesystem of about 11 TB = storage. The grade of the corruption is unclear but I have been able to= salvage many files using file carving techniques. However it would be = very convenient to get the filesystem in a somewhat working state to ex= tract folder structures and/or filenames. I tried to run a general file= system check, which finds a lot of overwritten data and plenty of thing= s wrong with inodes. However a few seconds or minutes in all three tool= s start to fill memory on the machine very good, until it is full and t= hey get ended by the OOM killer. At the beginning there was about 8 GB memory in the machine, which I la= ter bumped up to 16 GB specifically because I found references such as: https://serverfault.com/questions/9218/running-out-of-memory-running-fs= ck-on-large-filesystems https://unix.stackexchange.com/questions/689714/fsck-ext4-consumes-all-= memory-and-gets-killed https://groups.google.com/g/linux.debian.user/c/tLWRzDDsYY4 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=3D614082 Which all more or less came down to not having enough memory, so I want= ed to try and fix that first. Settings such as scratch=5Ffiles was enabled with the location being on= a reasonably fast SSD, but that did not help either. I would like to still try and see what is possible, but I am kind of ou= t of ideas how. What would be the next steps to dive a little deeper as= to why the memory is filling up so fast? I suppose that many data on t= he filesystem, specifically towards the later end of the filesystem, is= actually perfectly fine. I am under the assumption that only a brief p= art of the beginning was overwritten. I was able to verify all superblo= cks on the block device except the very last one (block 2560000000). Us= ing mke2fs I figured where the superblocks should be located and used a= short script to verify the distances between them to make sure I hit t= he right offset for the filesystem, and do not by accident try to align= the filesystem starting on a backup superblock. I think the offset is right because upon trying to mount, it recognizes= the filesystem but tells =E2=80=9Cthe structure needs cleaning=E2=80=9D= . I am under the assumption that parts were overwritten because my pred= ecessor on the topic tried to recreate a new, clean filesystem or even = md raid on these disks, thinking this will not affect the data on them.= When I found them the partitions were wiped and some of the data overw= ritten. All the superblocks however seem to have survived and the actua= l data also, because I could already verify the results of the filecarv= ing to be actual very good data. Best regards, looking forward to some interesting insights, M. S.