From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Wittig Subject: Re: raid5 - failed disks Date: Fri, 01 Apr 2005 12:33:46 +0200 Message-ID: <424D238A.8030305@weisshuhn.de> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigEA90574B936889FABCA40120" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Alvin Oga Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigEA90574B936889FABCA40120 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Alvin Oga wrote: > hi ya raiders .. > > we(they) have 14x 72GB scsi disks config'd as raid5, > ( no hot spare .. ) > > - if 1 disk dies, no problem ... ez to recover right. if one dies raid does exactly what is's supposed to do... > - my dumb question is, > - if 2 disks dies at the same time, i if 2 disks fail at the same time you data is lost. if you have raid5 with 5 hot spares and a second disk dies, befor a hot spare is synced into the array (will be listed as spare until sync hast finished) the same - data gone. > - i think 4x 300GB ide disks is better ( less likely to fail ?? ) it's a simple calculation. if one disk fails with a risk of 1 to 100000, then 10 disks fail with 10 to 100000. which means that having 10 disks is two times as dangerous as having 5 disks. if i had an array with as much disks as you have i would chose raid level 6 (not sure if dm supports this by now). raid level 6 survives two disks failing at once. btw: what reason is there to switch off air conditioning of your it equipment. temperature changes are poison to this fragile things. greetings, frank --------------enigEA90574B936889FABCA40120 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFCTSOQx6tzaD9P7mkRAk2wAJ9XeRJGo9xk/t6+VY01naCpnApU2QCfS9ci FLjap5JM2jdyRhO0FFPfgP8= =lo75 -----END PGP SIGNATURE----- --------------enigEA90574B936889FABCA40120--