From owner-freebsd-scsi@FreeBSD.ORG Sun Oct 24 19:02:25 2010 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5F03C1065672; Sun, 24 Oct 2010 19:02:25 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 8C06D8FC37; Sun, 24 Oct 2010 19:02:24 +0000 (UTC) Received: by fxm17 with SMTP id 17so2245610fxm.13 for ; Sun, 24 Oct 2010 12:02:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :x-enigmail-version:content-type:content-transfer-encoding; bh=t2XK6mZXDm5Wwtz6phu/TV6xl7YIMHCshDJozq0yOWY=; b=npk/1j1cINlkdinZ4sPcaVYz5olBh/Y7jPDIL+z08fAgN8/Axnf3RDztyVAigTxSp5 nOhywIMp0lf051MPeegIRwkpr4vySZV6P7uNsAmuDwvMdIN+lVqJNazwYpkrSrpK0xO/ PVBuSn+0XZUq6BFzdd0CAKzcH0hj64y8MHOEQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=uxPtMfZtdv0CvTS1vkPhu9xfF8/lj7L32Xh//bcuBErsplLVFElxw4YUpFboSqDSzA 4rdu45f8uCvUY1CFN/oytqtSpXuw4e7iZHQFl4QlSt5ToVPQWEhsVNdiIDIAXzLAoRca icHmwxVC7vcvSKwiBdj+PcmQ7iNLi2WcWIkcQ= Received: by 10.103.224.5 with SMTP id b5mr5250307mur.58.1287946943213; Sun, 24 Oct 2010 12:02:23 -0700 (PDT) Received: from mavbook2.mavhome.dp.ua (pc.mavhome.dp.ua [212.86.226.226]) by mx.google.com with ESMTPS id d20sm1330058fav.14.2010.10.24.12.02.21 (version=SSLv3 cipher=RC4-MD5); Sun, 24 Oct 2010 12:02:22 -0700 (PDT) Sender: Alexander Motin Message-ID: <4CC482BB.90102@FreeBSD.org> Date: Sun, 24 Oct 2010 22:02:19 +0300 From: Alexander Motin User-Agent: Thunderbird 2.0.0.23 (X11/20091212) MIME-Version: 1.0 To: Tijl Coosemans References: <201009161742.24228.tijl@coosemans.org> <20101024011854.GB78293@freebsd.org> <4CC4633D.4070605@FreeBSD.org> <201010242031.09656.tijl@coosemans.org> In-Reply-To: <201010242031.09656.tijl@coosemans.org> X-Enigmail-Version: 0.96.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, freebsd-scsi@freebsd.org, Oliver Fromme , Alexander Best Subject: Re: Summary: Re: Spin down HDD after disk sync or before power off X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 24 Oct 2010 19:02:25 -0000 Tijl Coosemans wrote: > On Sunday 24 October 2010 18:47:57 Alexander Motin wrote: >> I am not sure, but have feeling that tape drives (for example) may >> also benefit from head parking before powering down. > > USB hard disks would benefit as well I think. Although, ideally it > should happen after unmounting the last file system. Depending on unmount would be excessively aggressive. Far from every device close will be followed by unplugging. Same time nobody denies to run `camcontrol stop daX` before unplugging. USB disks are still "da". It would be more interesting to know if this practice applicable to other kinds of SCSI devices. -- Alexander Motin