From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolaus Rath Subject: How to use multiple backing devices Date: Mon, 08 Feb 2016 20:47:10 -0800 Message-ID: <87oabq8p81.fsf@vostro.rath.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from out2-smtp.messagingengine.com ([66.111.4.26]:42872 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754054AbcBIErM convert rfc822-to-8bit (ORCPT ); Mon, 8 Feb 2016 23:47:12 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id D017720BF0 for ; Mon, 8 Feb 2016 23:47:11 -0500 (EST) Received: from ebox.rath.org (ebox.rath.org [45.79.69.51]) by mail.messagingengine.com (Postfix) with ESMTPA id 82CDB6800D6 for ; Mon, 8 Feb 2016 23:47:11 -0500 (EST) Received: from vostro.rath.org (vostro [192.168.12.4]) by ebox.rath.org (Postfix) with ESMTPS id B1D1B1CD0B4 for ; Tue, 9 Feb 2016 04:47:10 +0000 (UTC) Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: linux-bcache@vger.kernel.org Hello, If I'm understanding Documentation/bcache.txt correctly, I should be able to use one SSD to cache multiple spinning disks. However, I'm at a loss of how to set this up in practice. I believe I need to do make-bcache -B /dev/sda # spinning rust make-bcache -B /dev/sdb # spinning rust=20 make-bcache -C /dev/sdc # ssd and then something like echo > /sys/block/bcacheX/bcache/attach But what do I have to put for X, and what for CSET-UUID? I believe for at least one of those values I will have two options (because there are two backing devices). Thanks, -Nikolaus (No Cc on replies please, I'm reading the list) --=20 GPG encrypted emails preferred. Key id: 0xD113FCAC3C4E599F =46ingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F =C2=BBTime flies like an arrow, fruit flies like a Banana.= =C2=AB