From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:44932 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728919AbfDSTJa (ORCPT ); Fri, 19 Apr 2019 15:09:30 -0400 Date: Fri, 19 Apr 2019 10:40:34 +0100 From: "Richard W.M. Jones" Subject: Re: [PATCH fio] engines: Add Network Block Device (NBD) support. Message-ID: <20190419094034.GB3926@redhat.com> References: <20190418140938.15527-1-rjones@redhat.com> 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: Sitsofe Wheeler Cc: fio , eblake@redhat.com, nbd@other.debian.org On Fri, Apr 19, 2019 at 10:27:49AM +0100, Sitsofe Wheeler wrote: > On Thu, 18 Apr 2019 at 15:10, Richard W.M. Jones wrote: > > If there are multiple jobs (files?) should these be striped over the > > block device? > > It depends on how you define the job. If you were to just copy the job > and give it a new name it would likely just overlap the first job > (because it's just going to do the same thing at the same time). You > would need to use something like numjobs > (https://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-numjobs > ) offset_increment > (https://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-offset-increment > ) and a workload that skipped (e.g. rw=write:12k - > https://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-readwrite > ) to achieve striping. I meant should the NBD engine stripe the jobs. Something like: job 0 gets to use the first bytes of the NBD device, job 1 gets to us the next bytes, etc. (Or actually striped/interleaved using a smaller block size). In other words it would be something hidden inside the NBD engine and not "visible" to fio. Thanks for the rest of the email - very helpful. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/