From owner-freebsd-questions@FreeBSD.ORG Mon Apr 13 10:56:26 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8D1B41065672 for ; Mon, 13 Apr 2009 10:56:26 +0000 (UTC) (envelope-from utisoft@googlemail.com) Received: from mail-ew0-f171.google.com (mail-ew0-f171.google.com [209.85.219.171]) by mx1.freebsd.org (Postfix) with ESMTP id E79018FC12 for ; Mon, 13 Apr 2009 10:56:25 +0000 (UTC) (envelope-from utisoft@googlemail.com) Received: by ewy19 with SMTP id 19so1907586ewy.43 for ; Mon, 13 Apr 2009 03:56:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:reply-to:in-reply-to :references:from:date:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=5UU6lsguqrkIpCMzbqA5B/JLEn+Nm/VoJ2R7Luesmgg=; b=Ao42gsKX7MBQwspeo9MKGNrQGxiOYqo+UxgQPWCJkXERZahrXS2KxBsPgExEURW/nN L0vkrMw00iD9+3PlmXHacxmy3hcS/0tQdN/lXZlgb8B8ViHN9RE1UPqBPFRBW55gWonr Eoru2PwujY6TOKjCu+tHmOrPurJkyP3vRzJAE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:reply-to:in-reply-to:references:from:date:message-id :subject:to:cc:content-type:content-transfer-encoding; b=VS/G6Y42Uwws6KpINp4MZcvV4x5o19no9RjIVbHsjvbZ6c4Y9sDJREb2OQnNfeBWch tR6RuEFFozZMolDHIsVgL6MxTSUhoT2WJmKqbfS7Db+spVaK2KuC6PZSabeYWyGnmMi6 8lmTpsi36LOjEhiSPel1+nCVJPdkNdr9Lo91A= MIME-Version: 1.0 Received: by 10.210.78.16 with SMTP id a16mr1883099ebb.14.1239620184286; Mon, 13 Apr 2009 03:56:24 -0700 (PDT) In-Reply-To: <49deb5d1.syt1ug/OWLKGHOGd%perryh@pluto.rain.com> References: <49de2c9a.QlCBOleCO/iBrMcf%perryh@pluto.rain.com> <20090409181009.GA38361@slackbox.xs4all.nl> <49de50cb.gcYrr9F1eSmdUBu9%perryh@pluto.rain.com> <20090410003759.dede9c9e.freebsd@edvax.de> <49deb5d1.syt1ug/OWLKGHOGd%perryh@pluto.rain.com> From: Chris Rees Date: Mon, 13 Apr 2009 11:56:09 +0100 Message-ID: To: perryh@pluto.rain.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd@edvax.de, freebsd-questions@freebsd.org Subject: Re: USB SD-card reader recognized, but not working, on 6.1 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: utisoft@gmail.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Apr 2009 10:56:26 -0000 2009/4/10 : > Polytropon wrote: >> On Thu, 09 Apr 2009 12:47:23 -0700, perryh@pluto.rain.com wrote: >> > It's an SD card, not a "drive", so I had not expected it to be >> > partitioned; but yes, it is: >> > >> > $ ls -l /dev/da0* >> > crw-r----- =A01 root =A0operator =A0 =A00, 244 Feb 14 15:09 /dev/da0 >> > crw-r----- =A01 root =A0operator =A0 =A00, 245 Feb 14 15:09 /dev/da0s1 >> >> Why don't you expect this? As far as I know, if something is >> msdosfs-formatted (read: any "Windows" readable file system, >> FAT), it always involves a "slice device". I never found a >> situation where access to /dev/da0 would work. > > My experience is exactly the reverse. =A0I've never before seen a > removable-media device (floppy, Zip-drive, JAZ drive) that *did* > have a DOS "partition" table aka BSD "slice" table. =A0Surely you > would not expect a USB floppy to show up as /dev/da0s1? > > AFAIK the reason for creating slices is to identify sections of > the device for use by different OS -- something often needed > for multi-boot from a hard drive but seldom on removable media. > I sure wasn't planning to use part of this SD card for my camera > to store pictures on, and the rest for FreeBSD backups :) Aha, careful. A flash drive/card is more like a removable hard drive. Since it's so much bigger than a floppy etc (typically) it makes sense to have a proper slice (partition) structure. If you want to boot off a floppy, it's a different operation from booting off a HDD for precisely this reason. Whereas a floppy isn't a proper, 'fixed' type disk; it's a tiny thing, suitable for max ~10 files. There's no need to have the overhead of a partition table, MBR etc. Same with CDs, booting off them involves several strange fudges (El Torito). Since a flash card would be a sensible thing to boot off, the designers want it to look more like a hard drive; as well as having the flexibility. Chris --=20 A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?