From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:33951 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755635AbcILCAW (ORCPT ); Sun, 11 Sep 2016 22:00:22 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1bjGXd-0003nT-QX for linux-btrfs@vger.kernel.org; Mon, 12 Sep 2016 04:00:13 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: Small fs Date: Mon, 12 Sep 2016 02:00:04 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Chris Murphy posted on Sun, 11 Sep 2016 14:33:18 -0600 as excerpted: > Something else that's screwy in that bug that I just realized, why is it > not defaulting to mixed-block groups on a 100MiB fallocated file? I > thought mixed-bg was the default below a certain size like 2GiB or > whatever? You apparently missed the memo... Newer btrfs-progs mkfs.btrfs no longer defaults under-1-GiB to mixed-bg mode, tho it remains very strongly recommended below 1 GiB, and soft- recommended to somewhere between 4 and 32 GiB (I believe the wiki says 5 GiB at this point but don't know how it arrived at that, but the numbers I've seen suggested on-list range between 4 and 32 GiB, as above). The explanation of why, based on the thread where I remember it coming up, was because defaulting to mixed-mode was making testing more complex. Don't ask me to agree with that because I most certainly don't; IMO sane defaults for normal use, which everyone seems to agree mixed- mode for under a GiB is, should apply, and if testing needs special- cased, well, special-case it. But none-the-less, that's the context in which it was agreed to do away with the mixed-mode default, despite it still being extremely strongly recommended for under a GiB. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman