From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from merlin.infradead.org ([205.233.59.134]:44555 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753381Ab3ARUk7 (ORCPT ); Fri, 18 Jan 2013 15:40:59 -0500 Date: Fri, 18 Jan 2013 21:40:40 +0100 From: Jens Axboe Subject: Re: fio is being killed by the oom-killer after fio verify runs for some time ~13 hours Message-ID: <20130118204040.GT3571@kernel.dk> References: <20130111091010.GA32674@kernel.dk> <50F12401.8090606@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: brian arb Cc: fio@vger.kernel.org On Fri, Jan 18 2013, brian arb wrote: > adding the option --verify_backlog=1024 resolved my issue. > On a side note how would one determine what the optimum number is for this > option? It's easier if you know the internals... The version you are running will store some metadata for each block written, for verification purposes. Standard install is 80 bytes per block. So if you have a 2TB disk and use 4K IO sizes, the memory required runs into the gigabytes. Quite unfortunate, really, will be fixed up shortly. In any case, with a backlog of just 1024, you wont use more than 80KB memory for verifies. So you could easily size it larger. I'd improve the option documentation, but I think it's better to just improve fio to not require the stored meta data to be able to verify. It will be in the 2.0.14 release. -- Jens Axboe