From owner-freebsd-arm@freebsd.org Sat Mar 3 00:32:30 2018 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 30067F3159F for ; Sat, 3 Mar 2018 00:32:30 +0000 (UTC) (envelope-from tech-lists@zyxst.net) Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D4DA08246D for ; Sat, 3 Mar 2018 00:32:29 +0000 (UTC) (envelope-from tech-lists@zyxst.net) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 1742120C05; Fri, 2 Mar 2018 19:32:29 -0500 (EST) Received: from frontend2 ([10.202.2.161]) by compute4.internal (MEProxy); Fri, 02 Mar 2018 19:32:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zyxst.net; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=fm2; bh=APHf8cBbkOO0FZ5U+IthLzpFjKcdD SPOZsnEQdkTLlA=; b=pLUHF7O15CFBKjrTbpDO/Vlghz06QM3H0P+CkiQqphTTa vO+qiKGVVQnzp6MOehr6vLZ8hjnoKpXCcfjPx0dXVrjD8hqQKkfBYa7rWN+XnXfl lwHqvjTBbdSb1DtdYvwcePZ6jqdXk+4xH6p54mbvz5sPWMomoUZryHlLYMs05NiQ miaN+0K3nkVBB8okuUm91OIrJYg6tUF2qiVUz/SfOYYLeb/C/Kaoae8Ayqh9btJ9 nD5d7I3i70ci4siZjd+2CjrwDt1cVGCpeo0KJgpIN9aCXo+ECKwbmlIxuP8W2CgB nb0JqMlsCimSpScO/SUdexMDR4JEh0UUS0E2twsbQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=APHf8c BbkOO0FZ5U+IthLzpFjKcdDSPOZsnEQdkTLlA=; b=eoj8H7FTuxGYHIQ6gEHMy0 7EyO9RQc3E9+WnP0boEmcvj6jR1Shjm86pZEQRq4wuaTDiNJi7c8RO4r1uriJJry GI2lCcQTnxjvcCZ7yJWnupDVf0OEQ4p0sfeD+CHSHiCtcekWUkNESpxyc/ZSuoYX AIc89onMj2jxxUoXxNebTeiLgWo0LpGZwGLjM6/WcBkls6HpYHwOzLKlVfNK8bLC 4iZ8CjpYzkJ61Cj1jBeLtFnMRZKJGcMWMQ0NA8EsUAauwQlOtFJJh6N8A273q50z t7dK0xXWX/q73IDPYpDkvKIA1DWSp03uR8qoouCw7Ts7Vl+6dmrvIwshw0oAlucw == X-ME-Sender: Received: from desktop.local (parsley.growveg.org [82.70.91.97]) by mail.messagingengine.com (Postfix) with ESMTPA id 93081246C8; Fri, 2 Mar 2018 19:32:28 -0500 (EST) Subject: Re: Can two USB flash drives conflict with each other? To: bob prohaska References: <20180302231317.GA37148@www.zefox.net> From: tech-lists Cc: freebsd-arm@freebsd.org Message-ID: <0fd4b991-a7d8-0e04-7d73-26d351873390@zyxst.net> Date: Sat, 3 Mar 2018 00:32:27 +0000 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180302231317.GA37148@www.zefox.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Mar 2018 00:32:30 -0000 On 02/03/2018 23:13, bob prohaska wrote: > The obvious solution is "don't do that!", but if somebody can offer > a more insightful explanation I'd be grateful. Using two USB flash > drives simultaneously would be very useful. I've found [this was a year ago, maybe two] that if I had two usb sticks plugged in that sometimes they'd be detected in reverse order to what I expected. What I mean is that sometimes the device called /dev/da0 and the one called /dev/da1 would swap on reboot. I suppose it would depend on which one woke up first. So if I had made /dev/da0p1, allocated it as swap, /dev/da0p1 as data, perhaps put the ports tree there, /dev/da1p1 as data, perhaps used the entire device for data, sometimes it'd boot, look at /dev/da0 which was /dev/da1 previously, not seen swap, and complained loudly. I think there is a way to wire device identities to names but it might need GPT rather than MBR as a partitioning scheme. I worked around it by labelling one of the usb sticks with sticky tape and ensuring it wasn't plugged in before the other one when rebooting. -- J.