Date: Mon, 12 Apr 1999 18:34:09 -0400 From: Bob Fritz <rfritz@us.oracle.com> To: questions@freebsd.org Subject: I get a ``panic: cant mount root'' error when rebooting the system after installation. Message-ID: <371274E0.2CB913B4@us.oracle.com>
next in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format. --------------7F2DBBB1CED25216857B92A9 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I get this error after installing 3.1 on a dedicated scsi drive. The PC has 1 IDE Drive (bios 0) and 3 scsi drives, scsi id's 0,1 and 2. BSD is installed on scsi id 2. What boot string should I use to boot the OS? Thanks You http://www.freebsd.org/FAQ/FAQ49.html#49 --------------7F2DBBB1CED25216857B92A9 Content-Type: text/html; charset=us-ascii; name="FAQ49.html" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="FAQ49.html" Content-Base: "http://www.freebsd.org/FAQ/FAQ49.html" <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <TITLE>I get a ``panic: cant mount root'' error when rebooting the system after installation.</TITLE> </HEAD> <BODY text="#000000" bgcolor="#ffffff"> <IMG SRC="../gifs/bar.gif" ALT="Navigation Bar" WIDTH="565" HEIGHT="33" BORDER=0 usemap="#bar"> <map name="bar"> <area shape="rect" coords="1,1,111,31" href="../index.html" ALT="Top"> <area shape="rect" coords="112,11,196,31" href="../ports/index.html" ALT="Applications"> <area shape="rect" coords="196,12,257,33" href="../support.html" ALT="Support"> <area shape="rect" coords="256,12,365,33" href="../docs.html" ALT="Documentation"> <area shape="rect" coords="366,13,424,32" href="../commercial/commercial.html" ALT="Vendors"> <area shape="rect" coords="425,16,475,32" href="../search/search.html" ALT="Search"> <area shape="rect" coords="477,16,516,33" href="../search/index-site.html" ALT="Index"> <area shape="rect" coords="516,15,562,33" href="../index.html" ALT="Top"> <area shape="rect" href="../index.html" coords="0,0,564,32" ALT="Top"> </map> <br clear=all> <A HREF="FAQ.html"><EM>Frequently Asked Questions for FreeBSD 2.X</EM></A> <b>:</b> <A HREF="FAQ24.html"><EM>Installation</EM></A> <b>:</b> <EM>I get a ``panic: cant mount root'' error when rebooting the system after installation.</EM><BR> <b>Previous:</b> <A HREF="FAQ48.html"><EM>The boot floppy starts but hangs at the ``Probing Devices...''</EM></A><BR> <b>Next:</b> <A HREF="FAQ50.html"><EM>What are the limits for memory?</EM></A> <HR NOSHADE> <H2><A NAME="49"></A>2.25. I get a ``panic: cant mount root'' error when rebooting the system after installation.</H2> <p>This error comes from confusion between the boot block's and the kernel's understanding of the disk devices. The error usually manifests on two-disk IDE systems, with the hard disks arranged as the master or single device on separate IDE controllers, with FreeBSD installed on the secondary IDE controller. The boot blocks think the system is installed on wd1 (the second BIOS disk) while the kernel assigns the first disk on the secondary controller device wd2. After the device probing, the kernel tries to mount what the boot blocks think is the boot disk, wd1, while it is really wd2, and fails.</p> <p>To fix the problem, do one of the following:</p> <p> <ol> <li>At the Boot: prompt, enter <code>1:wd(2,a)kernel</code> and press Enter. If the system starts, then run the command <pre> echo "1:wd(2,a)kernel" > /boot.config </pre> to make it the default boot string.</li> <li>Move the FreeBSD disk onto the primary IDE controller, so the hard disks are consecutive.</li> <li><A href="../handbook/kernelconfig.html">Rebuild your kernel,</A> modify the wd configuration lines to read: <pre> controller wdc0 at isa? port "IO_WD1" bio irq 14 vector wdintr disk wd0 at wdc0 drive 0 # disk wd1 at wdc0 drive 1 # comment out this line controller wdc1 at isa? port "IO_WD2" bio irq 15 vector wdintr disk wd1 at wdc1 drive 0 # change from wd2 to wd1 disk wd2 at wdc1 drive 1 # change from wd3 to wd2 </pre> Install the new kernel. If you moved your disks and wish to restore the previous configuration, replace the disks in the desired configuration and reboot. Your system should boot successfully. </li> </ol> </p> <HR NOSHADE> <A HREF="FAQ.html"><EM>Frequently Asked Questions for FreeBSD 2.X</EM></A> <b>:</b> <A HREF="FAQ24.html"><EM>Installation</EM></A> <b>:</b> <EM>I get a ``panic: cant mount root'' error when rebooting the system after installation.</EM><BR> <b>Previous:</b> <A HREF="FAQ48.html"><EM>The boot floppy starts but hangs at the ``Probing Devices...''</EM></A><BR> <b>Next:</b> <A HREF="FAQ50.html"><EM>What are the limits for memory?</EM></A> <hr> <address> <a href="../mailto.html">freebsd-questions@freebsd.org</a><br> Updated April 12, 1999 </address> </BODY> </HTML> --------------7F2DBBB1CED25216857B92A9-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?371274E0.2CB913B4>