From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wols Lists Subject: Re: proactive disk replacement Date: Tue, 21 Mar 2017 15:29:29 +0000 Message-ID: <58D146D9.5000301@youngman.org.uk> References: <3FA2E00F-B107-4F3C-A9D3-A10CA5F81EC0@allygray.2y.net> <11c21a22-4bbf-7b16-5e64-8932be768c68@websitemanagers.com.au> <58D1244E.3040204@hesbynett.no> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <58D1244E.3040204@hesbynett.no> Sender: linux-raid-owner@vger.kernel.org To: David Brown , Reindl Harald , Jeff Allison , Adam Goryachev Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 21/03/17 13:02, David Brown wrote: > If you have to use two USB carriers for the whole process, try to make > sure they are connected to separate root hubs so that they don't share > the bandwidth. This is not always just a matter of using two USB ports > - sometimes two adjacent USB ports on a PC share an internal hub. Having built a bunch of desktop pcs from parts, I'd say adjacent ports almost certainly share an internal hub. Typically, a single mobo header will run a wire to a double slot at the front, or a double slot at the back. So plugging one in at the front, and one at the back, will get round this unless it's actually just one hub in the ?northbridge. Cheers, Wol