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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 A6B88C432BE for ; Thu, 29 Jul 2021 01:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D54F6103B for ; Thu, 29 Jul 2021 01:43:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233252AbhG2Bnb (ORCPT ); Wed, 28 Jul 2021 21:43:31 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:43194 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233140AbhG2Bnb (ORCPT ); Wed, 28 Jul 2021 21:43:31 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 8E029201CA; Thu, 29 Jul 2021 01:43:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1627523007; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6H6l78+GftseoMpOE6fL+dPAnn9sjxeM4mKvBgWb9as=; b=tMKpHdeR/I6K5a7dZlHopFh+8V+SiTrbo6ipmR1NdlwE/r+LbdaDjedcgrUm2i+7OD9kp5 MEb036qOyvd5Nff/K6vvin3VhFduh2PcVZ/NjgxSKDKY6ilJB3AB3MH+1QiMj8sdNbhprZ AmXBnaKQz9Gt70OwP+TNd04jaOdFfpU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1627523007; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6H6l78+GftseoMpOE6fL+dPAnn9sjxeM4mKvBgWb9as=; b=/ksdFLDHIKvesYSHQa/dIYVQVOTUif6f/Q0uC8Yxu4V7crlOJJgbjYruKUD2uQU8QlcwQ8 sQ07q1NyYwIJ1HAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id DEF6113481; Thu, 29 Jul 2021 01:43:23 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id RLvqJrsHAmEwDQAAMHmgww (envelope-from ); Thu, 29 Jul 2021 01:43:23 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 From: "NeilBrown" To: "Zygo Blaxell" Cc: "J. Bruce Fields" , "Neal Gompa" , "Wang Yugui" , "Christoph Hellwig" , "Josef Bacik" , "Chuck Lever" , "Chris Mason" , "David Sterba" , "Alexander Viro" , "linux-fsdevel" , linux-nfs@vger.kernel.org, "Btrfs BTRFS" Subject: Re: [PATCH/RFC 00/11] expose btrfs subvols in mount table correctly In-reply-to: <20210729012931.GK10170@hungrycats.org> References: <162742539595.32498.13687924366155737575.stgit@noble.brown>, <20210728125819.6E52.409509F4@e16-tech.com>, <20210728140431.D704.409509F4@e16-tech.com>, <162745567084.21659.16797059962461187633@noble.neil.brown.name>, , <20210728191431.GA3152@fieldses.org>, <20210729012931.GK10170@hungrycats.org> Date: Thu, 29 Jul 2021 11:43:21 +1000 Message-id: <162752300106.21659.7482208502904653864@noble.neil.brown.name> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, 29 Jul 2021, Zygo Blaxell wrote: > > I'm looking at a few machines here, and if all the subvols are visible to > 'df', its output would be somewhere around 3-5 MB. That's too much--we'd > have to hack up df to not show the same btrfs twice...as well as every > monitoring tool that reports free space...which sounds similar to the > problems we're trying to avoid. Thanks for providing hard data!! How many of these subvols are actively used (have a file open) a the same time? Most? About half? Just a few?? Thanks, NeilBrown