From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Mamedov Subject: Re: 3TB drives failure rate Date: Mon, 29 Oct 2012 02:49:56 +0600 Message-ID: <20121029024956.30edb309@natsu> References: <11510711257.20121028131527@oudeis.org> <20121029015910.018efb17@natsu> <20121029021643.1c9e3195@natsu> <46B8932A-58A5-4C1A-9C8C-DCCD5D3A1CD9@colorremedies.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/.kcNPc86EQtQAhe3i=O2JJl"; protocol="application/pgp-signature" Return-path: In-Reply-To: <46B8932A-58A5-4C1A-9C8C-DCCD5D3A1CD9@colorremedies.com> Sender: linux-raid-owner@vger.kernel.org To: Chris Murphy Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids --Sig_/.kcNPc86EQtQAhe3i=O2JJl Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sun, 28 Oct 2012 14:34:49 -0600 Chris Murphy wrote: > A drive that can sit there like a bump on the log for 2 minutes before it= issues an actual read failure on sector(s) means mdadm is likewise waiting= , and everything above it is waiting. That's a long hang. I'd not be surpri= sed to see users go for hard reset with such a system hang after 45 seconds= let alone 2 minutes. Which is not different from what you would get (the same hang) in a non-RAID environment on the same drive, so I don't see how this would be specificall= y a RAID-related problem. > Anyway, the idea mdadm users can't benefit from shorter ERC is untrue. Th= ey certainly can. But the open question is why would they be getting such l= ong error recovery times in the first place? 7 seconds is a long time. One thing is "benefit", i.e. just a comfort issue, to prevent pauses when a drive starts failing (but really... does that happen very often? and during those times do you really care so that there are no pauses for error recove= ry, or maybe you just want to replace the drive and still have your data safe?), and another thing is a complete RAID failure that you'd get with a hardware RAID controller simply because something is not within 7 seconds, which is the whole source of that vendor-supported myth of "non-RAID drives= ". --=20 With respect, Roman ~~~~~~~~~~~~~~~~~~~~~~~~~~~ "Stallman had a printer, with code he could not see. So he began to tinker, and set the software free." --Sig_/.kcNPc86EQtQAhe3i=O2JJl Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlCNmnQACgkQTLKSvz+PZwgW0ACdELfgWWfJ7KNcjo+9JI6juWdo qVUAn2eVpcANTF36hL3eyNLueGRgMxl0 =yboB -----END PGP SIGNATURE----- --Sig_/.kcNPc86EQtQAhe3i=O2JJl--