From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: A few remaining questions about installing to RAID-10 Date: Sat, 3 Oct 2009 18:55:34 +0200 Message-ID: <20091003165534.GA19189@rap.rap.dk> References: <275143.15844.qm@web38804.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <275143.15844.qm@web38804.mail.mud.yahoo.com> Sender: linux-raid-owner@vger.kernel.org To: adfas asd Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sat, Oct 03, 2009 at 07:12:55AM -0700, adfas asd wrote: > --- On Fri, 10/2/09, Ben DJ wrote: > > On Fri, Oct 2, 2009 at 5:30 AM, adfas asd > > wrote: > > > What I know is that 'offset' will boot and fail over. I don't know if 'far' will. I also know that .90 will boot and fail over. I don't know whether 1.x will. When building the array I tried to use 1.2 (as I thought it was newest/best) but there was a bitch at the beginning of boot and it wouldn't boot (for other reasons) so I reverted to .90. When I do it again I will likely use 1.0, given what I've recently learned here. I am surprised that raid10,o2 will fail over. But maybe your bootloader understands raidi10,o2. My understanding is that on the second copy of the disk, blocks are flipped, and thus unreadable as a simple boot device. > I am still confused about the benefits of far vs offset. Keld (the developer) says that although offset is newer, it's not necessarily better than far, only more compatible. I have not found any rigorous performance comparisons of far vs offset. I am not the developer of far, only the designer, and then I did a small patch. There are a number of performance comparisons of far and offset at http://linux-raid.osdl.org/index.php/Performance If you are employing a filesystem, then be sure to look at tests that also do so, to take advantage of the effects of the file system elevator algorithms and buffering. Best regards keld