From mboxrd@z Thu Jan 1 00:00:00 1970 From: Harald Dunkel Subject: Re: [linux-usb-devel] 2.6.0-test1: random errors for USB disk Date: Thu, 17 Jul 2003 22:47:59 +0200 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3F170B7F.9010000@Synopsys.COM> References: <3F16FFD0.9070905@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from us01smtp2.synopsys.com ([198.182.44.80]:16530 "EHLO kiruna.synopsys.com") by vger.kernel.org with ESMTP id S270872AbTGQUdQ (ORCPT ); Thu, 17 Jul 2003 16:33:16 -0400 In-Reply-To: <3F16FFD0.9070905@pacbell.net> List-Id: linux-scsi@vger.kernel.org To: David Brownell Cc: Alan Stern , USB Storage List , SCSI development list David Brownell wrote: > Alan Stern wrote: > >> The information in your system logs is very clear. Your USB drive >> worked just great until it received a big data transfer. >> >> Under 2.4, the largest WRITE transfer was 130048 bytes and it worked >> fine. Under 2.6, the largest attempted WRITE transfer was 524288 >> bytes and it >> crashed the drive. The two commands were otherwise identical. > > > Just to clarify: there's another difference, and that's that 2.4 does > doing that smaller write one page at a time (write, wait, write, wait,...) > while 2.6 does it all at once (write, write, write, write, ... wait). > > That difference is how I've seen usb-storage top 30 MByte/sec on USB > with 2.6 kernels, when 2.4 may not reach 10 MB/sec on the same hardware. > I am using the disk in question to do backups of my $HOME. On 2.4.21 it was written with an amazing speed of about 20 MByte/sec, which I had never expected. I could live with 10, if it is reliable. Regards Harri