From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Raid selection questions (10 vs 6, n2 vs f2) on an 8 drive array Date: Sat, 19 Feb 2011 14:59:53 +1100 Message-ID: <20110219145953.24fb31f0@notabene.brown> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Larry Schwerzler Cc: linux-raid List-Id: linux-raid.ids On Fri, 18 Feb 2011 12:55:05 -0800 Larry Schwerzler wrote: > 2. One problem I'm having with my current setup is the esata cables > have been knocked loose which effectively drops 4 of my drives. I'd > really like to be able to survive this type of sudden drive loss. if > my drives are /dev/sd[abcdefgh] and abcd are on one esata channel > while efgh are on the other is there what drive order should I create > the array with? I'd guess /dev/sd[aebfcgdh] would that give me > survivability if one of my esata channels went dark? Yes, in md/raid10 the multiple copies are an 'adjacent' devices (in the sequence given to --create). Of course, you wouldn't actually use the string /dev/sd[aebfcgdh] as that expands matches in alphabetical order.: $ echo /dev/sd[aebfcgdh] /dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf /dev/sdg /dev/sdh Instead use this: $ echo /dev/sd{a,e,b,f,c,g,d,h} /dev/sda /dev/sde /dev/sdb /dev/sdf /dev/sdc /dev/sdg /dev/sdd /dev/sdh NeilBrown