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=-4.0 required=3.0 tests=BAYES_00, 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 60BCFC433DF for ; Sat, 25 Jul 2020 06:02:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46739206D8 for ; Sat, 25 Jul 2020 06:02:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgGYGCc (ORCPT ); Sat, 25 Jul 2020 02:02:32 -0400 Received: from dcvr.yhbt.net ([64.71.152.64]:37880 "EHLO dcvr.yhbt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725874AbgGYGCb (ORCPT ); Sat, 25 Jul 2020 02:02:31 -0400 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id A947B1F5AE; Sat, 25 Jul 2020 06:02:31 +0000 (UTC) Date: Sat, 25 Jul 2020 06:02:31 +0000 From: Eric Wong To: linux-btrfs@vger.kernel.org Subject: mixing raid1 and raid0? Message-ID: <20200725055728.GA6238@dcvr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hey all, I've started using btrfs recently with old HDDs of various sizes in a btrfs raid1 pool. It seems pretty good from a flexibility and redundancy standpoint. However, things like temporary files, caches, etc. don't need to be raid1, and raid0 might allow me to reduce wear on HDDs; so I'd like to make part of it raid0 while keeping most of it raid1. If my btrfs is mounted as /mnt/btrfs, would the following do what I want? btrfs balance start -dconvert=raid1 -mconvert=raid1 /mnt/btrfs/precious btrfs balance start -dconvert=raid0 -mconvert=raid0 /mnt/btrfs/junk Or should I make a separate FS for temporary and disposable raid0 data? Thanks