From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: Iosched_switch error References: From: Jens Axboe Message-ID: <577C15F5.2040005@kernel.dk> Date: Tue, 5 Jul 2016 14:17:57 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Matthew Eaton , fio@vger.kernel.org List-ID: On 06/30/2016 06:05 PM, Matthew Eaton wrote: > Hi Jens, > > I have run into this error when using ioscheduler=noop in my job > files. I only run into the error when specifying unsupported devices > such as nvme or md raid device. Should this be a fatal error? I ask > because sometimes I want to run the same job on various devices. > > sudo fname=/dev/nvme0n1 ./fio seqread.ini > seq-read: (g=0): rw=read, bs=128K-128K/128K-128K/128K-128K, > ioengine=libaio, iodepth=32 > fio-2.12-3-g8a09 > Starting 1 process > fio: io scheduler noop not found > fio: pid=5541, err=22/file:backend.c:1306, func=iosched_switch, > error=Invalid argument IO scheduler switching can only work, if the device is using an IO scheduler. md/raid devices are not, and nvme is driven by blk-mq, which doesn't have an IO scheduler either. That's why these devices fail for you. -- Jens Axboe