From owner-freebsd-questions@FreeBSD.ORG Tue Sep 6 19:32:20 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AA07816A41F for ; Tue, 6 Sep 2005 19:32:20 +0000 (GMT) (envelope-from rsmith@xs4all.nl) Received: from smtp-vbr11.xs4all.nl (smtp-vbr11.xs4all.nl [194.109.24.31]) by mx1.FreeBSD.org (Postfix) with ESMTP id D027943D46 for ; Tue, 6 Sep 2005 19:32:19 +0000 (GMT) (envelope-from rsmith@xs4all.nl) Received: from slackbox.xs4all.nl (slackbox.xs4all.nl [213.84.242.160]) by smtp-vbr11.xs4all.nl (8.13.3/8.13.3) with ESMTP id j86JWGbp047276; Tue, 6 Sep 2005 21:32:16 +0200 (CEST) (envelope-from rsmith@xs4all.nl) Received: by slackbox.xs4all.nl (Postfix, from userid 1001) id 01611647D; Tue, 6 Sep 2005 21:32:15 +0200 (CEST) Date: Tue, 6 Sep 2005 21:32:14 +0200 From: Roland Smith To: Norberto Meijome Message-ID: <20050906193214.GA20117@slackbox.xs4all.nl> Mail-Followup-To: Norberto Meijome , FreeBSD Questions References: <431D9B74.7000409@meijome.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="RnlQjJ0d97Da+TV1" Content-Disposition: inline In-Reply-To: <431D9B74.7000409@meijome.net> User-Agent: Mutt/1.4.2.1i X-GPG-Fingerprint: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 X-GPG-Key: http://www.xs4all.nl/~rsmith/pubkey.txt X-GPG-Notice: If this message is not signed, don't assume I sent it! X-Virus-Scanned: by XS4ALL Virus Scanner Cc: FreeBSD Questions Subject: Re: [OT] Life expectancy of powered down hard drives.... 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: Tue, 06 Sep 2005 19:32:20 -0000 --RnlQjJ0d97Da+TV1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Sep 06, 2005 at 11:36:52PM +1000, Norberto Meijome wrote: > I read somewhere (sorry, cant remember where) that hard drives fail if=20 > not powered up every so often (not sure of time frames, but the=20 > discussion was about tapes still being better for backups than hard=20 > drives if planning for long term storage). It was also mentioned a=20 > "knock on the centre of the drive" to bring it back to life (??). >=20 > How much truth is in this? I have EIDE drives that I havent used in=20 > years and I just tested them and they work fine...but again, I've had an= =20 > instance of a new drive, used twice to backup some info and then left=20 > untouched for 10 months, and it wouldn't even spin up... When a disk spins down, the heads move to the landing zone, stop floating on an air-cushion that forms when the platters are spinning and come in contact with the platters. So the disk platters are lubricated to prevent wear and tear during stops/starts. Now in the past these lubricants used to become sticky over time, preventing the drive from starting up. I'm not sure if it is still a problem these days; my workstation is on 24/7. > Does this affect SCSI drives? I suppose it would be more likely to=20 > affect desktop-quality IDE / SATA drives... The difference between SCSI and IDE is in the controller. The underlying technology is the same. SCSI drives might be built to higher specifications though. The only real solution to the parking problem that I'm aware of is IBM's load/unload technology. See http://www.pcguide.com/ref/hdd/perf/qual/featuresHead-c.html Roland --=20 R.F.Smith (http://www.xs4all.nl/~rsmith/) Please send e-mail as plain text. public key: http://www.xs4all.nl/~rsmith/pubkey.txt --RnlQjJ0d97Da+TV1 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFDHe6+EnfvsMMhpyURAmFZAJ4yGFIcYQxBpuJTnYM/i6xA75q59gCgj9tf sOqK7+w4JableNnm64NKWSs= =51EG -----END PGP SIGNATURE----- --RnlQjJ0d97Da+TV1--