From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5019EC4321E for ; Sun, 27 Nov 2022 19:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229529AbiK0TvK (ORCPT ); Sun, 27 Nov 2022 14:51:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbiK0TvI (ORCPT ); Sun, 27 Nov 2022 14:51:08 -0500 Received: from mail.thelounge.net (mail.thelounge.net [91.118.73.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A963064DC for ; Sun, 27 Nov 2022 11:51:05 -0800 (PST) Received: from [10.10.10.2] (rh.vpn.thelounge.net [10.10.10.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-256)) (No client certificate requested) (Authenticated sender: h.reindl@thelounge.net) by mail.thelounge.net (THELOUNGE MTA) with ESMTPSA id 4NKzjy3W1xzXLf; Sun, 27 Nov 2022 20:51:02 +0100 (CET) Message-ID: <5af32701-648c-973d-8ebb-73b7acec3ced@thelounge.net> Date: Sun, 27 Nov 2022 20:51:02 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: how do i fix these RAID5 arrays? Content-Language: en-US To: Wol , John Stoffel Cc: David T-G , Linux RAID list References: <20221123220736.GD19721@jpo> <20221124032821.628cd042@nvm> <20221124211019.GE19721@jpo> <25474.28874.952381.412636@quad.stoffel.home> <62b72b4e-8461-e616-1227-4dcef8853143@youngman.org.uk> <7316d29a-bab6-b8a2-5c77-803af8de378b@thelounge.net> <93df4fec-8057-c49e-f96e-d857542896fa@youngman.org.uk> From: Reindl Harald Organization: the lounge interactive design In-Reply-To: <93df4fec-8057-c49e-f96e-d857542896fa@youngman.org.uk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Am 27.11.22 um 20:30 schrieb Wol: > On 27/11/2022 18:23, Reindl Harald wrote: >>> In other words, if the filesystem is only using 10% of the disk, >>> supporting trim means that raid knows which 10% is being used and >>> only bothers syncing that! >> >> this is nonsense and don't reflect reality >> >> the only thing trim does is tell the underlying device which blocks >> can be used for wear-leveling >> > Then why do some linux block devices THAT HAVE NOTHING TO DO WITH > HARDWARE support trim? (Sorry I can't name them, I've come across them). to pass it down until it finally reaches the physical device > And are you telling me that you're happy with a block device trashing > your live data because the filesystem or whatever trimmed it? If the > file system sends a TRIM command, it's saying "I am no longer using this > space". What the underlying block layer does with it is up that layer. it's impressive how many nonsense one can talk! nothing is thrashing live-data! > An SSD might use it for wear leveling, I'm pretty certain > thin-provisioning uses it to release space (oh there's my block layer > that isn't hardware). so what? it's still the underlying device > AND THERE IS ABSOLUTELY NO REASON why md-raid shouldn't flag it as "this > doesn't need recovery" obviously it is > Okay, it would need some sort of bitmap to say > "these stripes are/aren't in use, which would chew up some disk space, > but it's perfectly feasible and here we are: it would need something which isn't there boy: for about 8 years everything you say on this mailing list is guessing while you try to sound like an expert i told you what is fact and you bubble about a perfect world which don't exist the same way as you pretended convert a degradeded RAID10 to RAID1 on double sized disks is easy because it's only change metadata which pretty clear showed that you have no clue what you are talking about! RAID10 is striped, RAID1 is mirrored please stop talking aboout things you have no clue about