Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 14 Feb 2001 16:35:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 14 Feb 2001 16:35:17 -0500 Received: from janus.cypress.com ([157.95.1.1]:20682 "EHLO janus.cypress.com") by vger.kernel.org with ESMTP id ; Wed, 14 Feb 2001 16:34:58 -0500 Message-ID: <3A8AF9F9.38D467EB@cypress.com> Date: Wed, 14 Feb 2001 15:34:49 -0600 From: Thomas Dodd Organization: Cypress Semiconductor Southeast Design Center X-Mailer: Mozilla 4.76 [en] (X11; U; SunOS 5.8 sun4u) X-Accept-Language: en-US, en-GB, en, de-DE, de-AT, de-CH, de, zh-TW, zh-CN, zh MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Jasmeet Sidhu Subject: Re: IDE DMA Problems...system hangs In-Reply-To: <5.0.2.1.2.20010214115941.02471bb8@pop.arraycomm.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jasmeet Sidhu wrote: > > Hey guys, > > I am attaching my previous email for additional info. Now I am using > kernel 2.4.1-ac12 and these problems have not gone away. > > Anybody else having these problems with a ide raid 5? > > The Raid 5 performance should also be questioned..here are some number > returned by hdparam > > /dev/hda - IBM DLTA 20GB (ext2) > /dev/md0 - 8 IBM DLTA 45GB (Reiserfs) > > [root@bertha hdparm-3.9]# ./hdparm -t /dev/hda > /dev/hda: > Timing buffered disk reads: 64 MB in 2.36 seconds = 27.12 MB/sec > > [root@bertha hdparm-3.9]# ./hdparm -t /dev/md0 > /dev/md0: > Timing buffered disk reads: 64 MB in 22.16 seconds = 2.89 MB/sec > > Is this to be expected? This much performance loss? Anybody else using > IDE raid, I would really appreciate your input on this setup. md2 = RAID0 ext2 hda = hdb = IBM DTTA-351010 (10GB, 5400RPM, UDMA33) # hdparm -tT /dev/hda /dev/md2 /dev/hda: Timing buffered disk reads: 64 MB in 5.27 seconds = 12.14 MB/sec Timing buffer-cache reads: 128 MB in 0.82 seconds =156.10 MB/sec /dev/md2: Timing buffered disk reads: 64 MB in 3.34 seconds = 19.16 MB/sec Timing buffer-cache reads: 128 MB in 0.80 seconds =160.00 MB/sec On AMD K7 w/ 7409 (Viper) chipset, DMA66 mode w/ 80-pin cable. kernel = 2.4.1-ac8, no errors in kernel log. So I get a 58% increase. You should almost max out the bus. You probably have a bad cable. Try hdparam on each disk and see if any of them have errors/ cause the lockup. -Thomas - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/