From owner-freebsd-stable Sat Aug 14 15: 5:10 1999 Delivered-To: freebsd-stable@freebsd.org Received: from point.osg.gov.bc.ca (point.osg.gov.bc.ca [142.32.102.44]) by hub.freebsd.org (Postfix) with ESMTP id 3B7D914BCC for ; Sat, 14 Aug 1999 15:05:01 -0700 (PDT) (envelope-from cy@cschuber.net.gov.bc.ca) Received: (from daemon@localhost) by point.osg.gov.bc.ca (8.8.7/8.8.8) id PAA20793; Sat, 14 Aug 1999 15:07:18 -0700 Received: from da007.inetex.com(139.142.118.22), claiming to be "cwsys.cwsent.com" via SMTP by point.osg.gov.bc.ca, id smtpda20791; Sat Aug 14 15:07:11 1999 Received: (from uucp@localhost) by cwsys.cwsent.com (8.9.3/8.9.1) id OAA75747; Sat, 14 Aug 1999 14:04:46 -0700 (PDT) Message-Id: <199908142104.OAA75747@cwsys.cwsent.com> Received: from localhost.cwsent.com(127.0.0.1), claiming to be "cwsys" via SMTP by localhost.cwsent.com, id smtpdO75743; Sat Aug 14 14:04:04 1999 X-Mailer: exmh version 2.0.2 2/24/98 Reply-To: Cy Schubert - ITSD Open Systems Group From: Cy Schubert - ITSD Open Systems Group X-OS: FreeBSD 2.2.8-RELEASE X-Sender: cy To: Mike Meyer Cc: stable@FreeBSD.ORG Subject: Re: Random disk read problems In-reply-to: Your message of "Fri, 13 Aug 1999 22:28:56 PDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 14 Aug 1999 14:04:04 -0700 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message , Mike Meye r writes: > I've been shuffling some data around in preperation for archiving > it. Being a bit paranoid, I tend to md5 sum the stuff at both ends, > and then verify the checksums. > > I'm getting random differences. I.e. - the diff of the md5 sums will > turn up a file or two that are different. Running diff or cmp on them > by hand - and they're the same. Likewise, running md5 on them by hand > turns up correct sums. > > This worries me. I'm running an older version of 3.2-stable on a > SuperMicro motherboard with 256Meg of ram and a Seagate ST39173W SCSI > drive. Is this something that udpating the OS might fix, or am I > seeing evidence of hardware problems (but I'm not seeing anything in > syslog!), or possibly bugs in both diff and md5? I had a similar problem with a SCSI Zip drive attached to a 1542CF, primarily when the Zip drive was being used simultaneously while other SCSI devices were using the SCSI bus. In my case, corrupted data was being written to the Zip drive. Replacing the 1542CF with a 2940UW solved the problem. In the mean time I've reinstalled the 1542CF and only attached the Zip drive to it, leaving 2 SCSI disks, a CDROM drive and a 4mm DAT attached to the 2940UW. This configuration has worked for a number of months without problems. I've been told that 1542's do not work well with multi-user/multi-taskin g O/S's. I'm not sure what SCSI controller you're using. Could it be that your controller is corrupting data when it is "very" busy? Other than that, additional information will be needed to diagnose the problem, including a uname -a, dmesg output, and a copy of your kernel config file posted to this list. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Open Systems Group Internet: Cy.Schubert@uumail.gov.bc.ca ITSD Cy.Schubert@gems8.gov.bc.ca Province of BC "e**(i*pi)+1=0" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message