From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mario 'BitKoenig' Holbe Subject: Re: Proactive Drive Replacement Date: Tue, 21 Oct 2008 17:30:18 +0200 Message-ID: References: <48FD94F9.3060400@dgreaves.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids David Lethe wrote: > is correctly called the "SMART selective > self-test routine". By the way, this is an OFF-LINE scan. short, long, conveyance and selective tests are all offline. > So bottom line, Mario is correct in that there is a way to get a PARTIAL > list of bad blocks, if you have a disk > that supports this command, and you're willing to run an off-line scan > (not practical or a parity-protected RAID > environment). Most modern (ATA) disks support "Suspend Offline collection upon new command". Well, the tests take notably longer on a loaded disk and (low-frequent) requests to that disk take notably longer as well (high-frequent requests just keep the test suspended), but it works. > It is possible that some vendor has implemented a SATA ON-LINE bad block > scanning mechanism that reports results and > doesn't kill I/O performance. It would have to give full list of bad > blocks, or at least startingblock + range. > > That would be wonderful as you could just read the list on regular > interval and rebuild stripes as necessary. You'd have > Self-healing parity. echo check > /sys/block/mdx/md/sync_action That's indeed way more powerful than any attempt to rely on any S.M.A.R.T. thingy. regards Mario -- I thought the only thing the internet was good for was porn. -- Futurama