Date: Mon, 13 Jul 2009 09:20:03 GMT From: Dan Naumov <dan.naumov@gmail.com> To: freebsd-geom@FreeBSD.org Subject: Re: kern/121481: [gmirror] data rot on disk with gmirror Message-ID: <200907130920.n6D9K3bL055032@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR kern/121481; it has been noted by GNATS. From: Dan Naumov <dan.naumov@gmail.com> To: "Steiner, Bernard" <Bernard.Steiner@lahmeyer.de> Cc: bug-followup@freebsd.org Subject: Re: kern/121481: [gmirror] data rot on disk with gmirror Date: Mon, 13 Jul 2009 12:16:33 +0300 On Mon, Jul 13, 2009 at 11:50 AM, Steiner, Bernard<Bernard.Steiner@lahmeyer.de> wrote: >> [checksumming utilities] > > Please explain how to do that on both sides of a gmirror. > AFAIK, gmirror can be configured in the following ways: > (1) always read from "primary" disk => cannot check secondary > (2) round robin or load => read cannot be reliably reproduced > > Correct me if I am wrong, but this does not seem like a solution > to my problem. You have several options: Option 1 (this has the benefit of working with all balance algorithms): Take disc2 offline, run checksum check (so that checks are done against disc1) Take disc2 online, take disc1 offline, run checksum check Option 2 (for "prefer" algorithm): Assuming disk1 is the promoted disk, run checksum check Promote disk2, run checksum check Promote disk1 to return to original state - Sincerely, Dan Naumov
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200907130920.n6D9K3bL055032>