From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Wilck Subject: Re: How does md(adm) work with fake-raid ? Date: Fri, 19 Jul 2013 20:52:31 +0200 Message-ID: <51E98AEF.5060206@arcor.de> References: <51E86613.9050505@arcor.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Francis Moreau , linux-raid@vger.kernel.org List-Id: linux-raid.ids > Yes, but my question is about how md cooperate with the BIOS in this case ? Not sure what you mean. When Linux runs, with or without MD, no BIOS code is ever executed. The only way of communication between BIOS and MD is the meta data. When you create an array in your BIOS setup tool, The BIOS will write the meta data. MD will read it, and when it's done, it will re-write it (usually unchanged, unless a disk failure occurs, but there are some fields such as sequential numbers and time stamps that change every time the meta data is written). The BIOS will read this back the next time your system boots. > Are there any procedures described out there that I could follow to > test MD DFF ? Not really. Play around, test various RAID levels etc, whatever your fake RAID supports. If you have a Linux or Windows driver for your fake raid, check if it correctly detects your setup after MD had control. Note that RAID arrays *created* by MD (with mdadm -C) will most probably not be accepted by the BIOS (it will consider them "foreign configurations" and not import them). Martin