From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f50.google.com ([74.125.82.50]:40847 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799AbdKWLsD (ORCPT ); Thu, 23 Nov 2017 06:48:03 -0500 Received: by mail-wm0-f50.google.com with SMTP id b189so15943173wmd.5 for ; Thu, 23 Nov 2017 03:48:02 -0800 (PST) Message-ID: <1511437679.14360.14.camel@gmail.com> Subject: Re: notification about corrupt files from "btrfs scrub" in cron From: ST To: Duncan <1i5t5.duncan@cox.net> Cc: linux-btrfs@vger.kernel.org Date: Thu, 23 Nov 2017 13:47:59 +0200 In-Reply-To: References: <1511380450.1675.94.camel@gmail.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: > > I have following cron job to scrub entire root filesystem (total ca. > > 7.2TB and 2.3TB of them used) once a week: > > /bin/btrfs scrub start -r / > /dev/null > > > > Such scrubbing takes ca. 2 hours. How should I get notified that a > > corrupt file was discovered? Does this command return some error code > > back to cron so it can send an email as usual? Will cron wait 2 hours to > > get that code? > > > > I tried that command once without "> /dev/null" but got no email > > notification about the results (eventhough the check was OK) - why? > > See the btrfs-scrub manpage... > > Note that normally btrfs scrub start is asynchronous and should return > effectively immediately, the only possible errors therefore being for > example if the given path doesn't point to a btrfs or btrfs-device (which > would return a status code of 1, scrub couldn't be performed), etc. > > Status can be checked via btrfs scrub status, and/or, or you can use the > btrfs scrub start's -B (don't background) switch, which will cause it to > wait until the scrub is finished and print a summary report. That should > allow you to check for a status code of 3, scrub found uncorrectable > errors, as well. Thank you for the response! Does it mean that if write: /bin/btrfs scrub start -r -B / cron will hang for 2 hours (is it problematic?) and then send me an email with the summary report (even if everything was OK), and if I write: /bin/btrfs scrub start -r -B / > /dev/null after 2 hours it will send an email, only if there was an error with whatever error code (1-3)? Thank you!