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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F02FC433DF for ; Wed, 20 May 2020 21:02:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51B5C2075F for ; Wed, 20 May 2020 21:02:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728102AbgETVCM (ORCPT ); Wed, 20 May 2020 17:02:12 -0400 Received: from freki.datenkhaos.de ([81.7.17.101]:35614 "EHLO freki.datenkhaos.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727083AbgETVCM (ORCPT ); Wed, 20 May 2020 17:02:12 -0400 X-Greylist: delayed 523 seconds by postgrey-1.27 at vger.kernel.org; Wed, 20 May 2020 17:02:11 EDT Received: from localhost (localhost [127.0.0.1]) by freki.datenkhaos.de (Postfix) with ESMTP id D3BEF2A7C086; Wed, 20 May 2020 22:53:26 +0200 (CEST) Received: from freki.datenkhaos.de ([127.0.0.1]) by localhost (freki.datenkhaos.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ro_Qzj3kFEiC; Wed, 20 May 2020 22:53:23 +0200 (CEST) Received: from latitude (x4dbe0cc2.dyn.telefonica.de [77.190.12.194]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by freki.datenkhaos.de (Postfix) with ESMTPSA; Wed, 20 May 2020 22:53:23 +0200 (CEST) Date: Wed, 20 May 2020 22:53:19 +0200 From: Johannes Hirte To: Zygo Blaxell Cc: Justin Engwer , linux-btrfs@vger.kernel.org Subject: Re: I think he's dead, Jim Message-ID: <20200520205319.GA26435@latitude> References: <20200520013255.GD10769@hungrycats.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200520013255.GD10769@hungrycats.org> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2020 Mai 19, Zygo Blaxell wrote: > > Corollary: Never use space_cache=v1 with raid5 or raid6 data. > space_cache=v1 puts some metadata (free space cache) in data block > groups, so it violates the "never use raid5 or raid6 for metadata" rule. > space_cache=v2 eliminates this problem by storing the free space tree > in metadata block groups. > This should not be a real problem, as the space-cache can be discarded and rebuild anytime. Or do I miss something? -- Regards, Johannes Hirte