From owner-freebsd-questions@FreeBSD.ORG Thu Jun 14 13:55:51 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0DF6E1065673 for ; Thu, 14 Jun 2012 13:55:51 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from mail2.nber.org (mail2.nber.org [66.251.72.79]) by mx1.freebsd.org (Postfix) with ESMTP id A0D9D8FC1C for ; Thu, 14 Jun 2012 13:55:50 +0000 (UTC) Received: from nber6 (nber6.nber.org [66.251.72.76]) by mail2.nber.org (8.14.4/8.14.4) with ESMTP id q5EDtfQ4065594; Thu, 14 Jun 2012 09:55:41 -0400 (EDT) (envelope-from feenberg@nber.org) Date: Thu, 14 Jun 2012 09:49:00 -0400 (EDT) From: Daniel Feenberg X-X-Sender: feenberg@nber6 To: Mike Clarke In-Reply-To: <201206141437.52763.jmc-freebsd2@milibyte.co.uk> Message-ID: References: <4FD967E8.60305@dreamchaser.org> <20120614080511.0d855639.freebsd@edvax.de> <201206141437.52763.jmc-freebsd2@milibyte.co.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Anti-Virus: Kaspersky Anti-Virus for Linux Mail Server 5.6.39/RELEASE, bases: 20120614 #8164821, check: 20120614 clean Cc: freebsd-questions@freebsd.org Subject: Re: USB device activity when not mounted X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Jun 2012 13:55:51 -0000 On Thu, 14 Jun 2012, Mike Clarke wrote: > On Thursday 14 June 2012 07:05:11 Polytropon wrote: >> I don't think that's a problem. I've got a USB stick here >> that has a blinkenlight as soon as it's powered on (plugged >> in), even if there is no reading / writing / mounting activity. >> >> After you've successfully performed umount, the USB stick _is_ >> synced and can safely be removed, no matter what you assume >> the funny lights want to tell you. >> Is it possible that there is volitile memory buffering in the stick that may not have been written to flash when umount thinks it is complete, and the flashing light is an indication that power is still required to complete the write to non-volitile memory? Futhermore, are we sure that umount even waits for a sync? There is no mention of that in the man page and I don't recall any long waits for umount to return. daniel feenberg