From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabio Muzzi Subject: MD raid and different elevators (disk i/o schedulers) Date: Thu, 29 Jul 2010 12:12:30 +0200 Message-ID: <4C51540E.9050005@kurgan.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids I have tried to find information about this question in google, but found nothing. The question is: are there issues using different disk i/o schedulers (by appending elevator=xxx to the kernel boot command line) when using md RAID1 or RAID5? I seem to remember that someone told me that using elevator=deadline can cause perfectly good disks to be kicked from the RAID because of some latency issues that make the disk seem unresponsive (and dead) to the raid software. Is this true? Are there compatibility issues using different i/o schedulers with software raid? Thanks -- Fabio "Kurgan" Muzzi (worried Linux sysadmin)