From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f181.google.com ([74.125.82.181]:49239 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751150Ab3CJOKG (ORCPT ); Sun, 10 Mar 2013 10:10:06 -0400 Received: by mail-we0-f181.google.com with SMTP id t44so2648673wey.40 for ; Sun, 10 Mar 2013 07:10:04 -0700 (PDT) Message-ID: <513C949C.6080009@gmail.com> Date: Sun, 10 Mar 2013 15:11:40 +0100 From: Goffredo Baroncelli Reply-To: kreijack@inwind.it MIME-Version: 1.0 To: Martin Steigerwald CC: linux-btrfs Subject: Re: [PATCH 0/5] [RFC] RAID-level terminology change References: <1362861071-12589-1-git-send-email-hugo@carfax.org.uk> (sfid-20130310_104347_651723_C84E4102) <201303101223.56805.Martin@lichtvoll.de> In-Reply-To: <201303101223.56805.Martin@lichtvoll.de> Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi Martin, On 03/10/2013 12:23 PM, Martin Steigerwald wrote: > Hi Hugo, > > Am Samstag, 9. März 2013 schrieb Hugo Mills: >> Some time ago, and occasionally since, we've discussed altering the >> "RAID-n" terminology to change it to an "nCmSpP" format, where n is the >> number of copies, m is the number of (data) devices in a stripe per copy, >> and p is the number of parity devices in a stripe. >> >> The current kernel implementation uses as many devices as it can in >> the striped modes (RAID-0, -10, -5, -6), and in this implementation, >> that is written as "mS" (with a literal "m"). The mS and pP sections are >> omitted if the value is 1S or 0P. >> >> The magic look-up table for old-style / new-style is: >> >> single 1C (or omitted, in btrfs fi df output) >> RAID-0 1CmS >> RAID-1 2C >> DUP 2CD > > What does the "D" in "2CD" mean? Its not explained above, unless I miss > something. This means DUP (two copy on the same disk); I understand that only reading the code. > > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5