From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrik Jonsson Subject: Re: Hard drive lifetime: wear from spinning up or rebooting vs running Date: Sun, 05 Feb 2006 21:25:33 -0800 Message-ID: <43E6DDCD.7090007@ucolick.org> References: <43E68D62.4080704@cogweb.net> <20060206035759.GB25631@sam.triumf.ca> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2CF2FA43F919252F379B26CE" Return-path: In-Reply-To: <20060206035759.GB25631@sam.triumf.ca> Sender: linux-raid-owner@vger.kernel.org Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2CF2FA43F919252F379B26CE Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Konstantin Olchanski wrote: >>Does anyone have an actual formula? > > > I doubt it, because it requires measuring lifetimes, which takes > years, by which time the data are useless because the disks you used > are obsolete. I found this article on drive reliability from Seagate: http://www.digit-life.com/articles/storagereliability/ They do indeed model the temperature derating as an exponential, such that 25C is the reference temp and at 30C the MTBF is reduced to 78%. Running the drive at 40C gives you half the lifetime. Can't find anything about spinup/down though, but they do talk about how MTBF depends on power-on hours per year, which should be a correlated quantity. They assume the MTBF goes *up* the fewer POH/yr the drive has, there's never any reduction due to excessive spinup/down, or at least the reduction is never dominant. They also talk about the effect of duty cycle. cheers, /Patrik --------------enig2CF2FA43F919252F379B26CE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (MingW32) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFD5t3ST+KvsdUW5p8RArzXAKCpB9c++tyAmf7TjVDnuXcTjjVHOgCfdln3 LXCvFPLw6XuEC3/L22h+kA0= =foNT -----END PGP SIGNATURE----- --------------enig2CF2FA43F919252F379B26CE--