From: "Martin K. Petersen" Subject: Re: How to use mkfs.ext4 "stride=" on RAID correctly? Date: Sat, 16 Jan 2010 00:38:19 -0500 Message-ID: References: <4B50AB23.8050300@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ric Wheeler , linux-ext4@vger.kernel.org To: Mike Mestnik Return-path: Received: from rcsinet12.oracle.com ([148.87.113.124]:18234 "EHLO rcsinet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750710Ab0APFjb (ORCPT ); Sat, 16 Jan 2010 00:39:31 -0500 In-Reply-To: (Mike Mestnik's message of "Fri, 15 Jan 2010 20:59:38 -0600") Sender: linux-ext4-owner@vger.kernel.org List-ID: >>>>> "Mike" == Mike Mestnik writes: >> Recent changes upstream export alignment and optimal IO size for you >> (at least for software RAID/dm devices) and for some external arrays >> if the vendor exports the information in a standard way. >> Mike> Would this include eSATA DAS units? Example: LaCie 4big Quadra No. Only SCSI devices report the necessary information. There are no comparable fields in ATA-ACS. Mike> I can't discover or alter the IO size on this device and have not Mike> received an answer from LaCie support. They did say something to Mike> the effect of "We don't have this information in our Mike> documentation, so it must be I.P. that I can't disclose." I.e. "we source this controller from a company in China and have no idea". -- Martin K. Petersen Oracle Linux Engineering