From owner-freebsd-questions@freebsd.org Wed Sep 14 22:52:27 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 1455FBDB84C for ; Wed, 14 Sep 2016 22:52:27 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: from cosmo.uchicago.edu (cosmo.uchicago.edu [128.135.70.90]) by mx1.freebsd.org (Postfix) with ESMTP id E7B90132E for ; Wed, 14 Sep 2016 22:52:26 +0000 (UTC) (envelope-from galtsev@kicp.uchicago.edu) Received: by cosmo.uchicago.edu (Postfix, from userid 48) id F0E61CB8CB0; Wed, 14 Sep 2016 17:52:19 -0500 (CDT) Received: from 128.135.52.6 (SquirrelMail authenticated user valeri) by cosmo.uchicago.edu with HTTP; Wed, 14 Sep 2016 17:52:19 -0500 (CDT) Message-ID: <33086.128.135.52.6.1473893539.squirrel@cosmo.uchicago.edu> In-Reply-To: <20160914233958.3ae5d3ae@gumby.homeunix.com> References: <42.56.05022.D3A48D75@dnvrco-oedge02> <64887.128.135.52.6.1473793846.squirrel@cosmo.uchicago.edu> <20160914233958.3ae5d3ae@gumby.homeunix.com> Date: Wed, 14 Sep 2016 17:52:19 -0500 (CDT) Subject: Re: Best kind of hard drive for heavy use? From: "Valeri Galtsev" To: "RW" Cc: freebsd-questions@freebsd.org Reply-To: galtsev@kicp.uchicago.edu User-Agent: SquirrelMail/1.4.8-5.el5.centos.7 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Sep 2016 22:52:27 -0000 On Wed, September 14, 2016 5:39 pm, RW via freebsd-questions wrote: > On Tue, 13 Sep 2016 14:10:46 -0500 (CDT) > Valeri Galtsev wrote: > >> I usually use HGST (formerly Hitachi, before that IBM); - He filled >> and sealed ones sound really good (we will know statistics on them >> some 5-7 years down the road, so now we can only guess). > > Personally I wouldn't want to risk it until then. These drives rely on > the helium atmosphere to work correctly, and helium is notoriously > difficult to contain in the long-term because it's a monatomic gas. My rusted knowledge of physics suggests me that this is absolutely correct if you keep helium in container at higher pressure than exterior environment pressure. If exterior pressure is the same as pressure inside sealed container, even if the seal is not perfect, sealed gas doesn't leak away as fast as when there is pressure difference - much slower. Also, seal made of metal, e.g. Indium, which is monoatomic substance itself (very soft, BTW, you can press out of syringe indium and make thin wire this way), may be extremely good to seal monoatomic gas. Valeri ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++