Hi all: I'm trying to rebuild the anaconda installer for Centos 4.0 (i386) to add some RPMs and do some other things, and I've run into a problem. I've done lots of anaconda rebuilds for Tao Linux 1.0, and I'm bringing those bits forward into Centos 4.0. The all-knowing web hasn't turned up anything useful. It looks like the PXE-loaded kernel unpacked and mounted the initrd OK, but then things went awry (quickly). Anyone seen this on a PXE boot of an anaconda build? <snip> RAMDISK: Compressed image found at block 0 VFS: Mounted root (ext2 filesystem). VFS: Cannot open root device "<NULL>" or unknown-block(3,2) Please append a correct "root=" boot option Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,2) Help or pointers to applicable docs very welcome. -- Dave Thompson ( thomas(at)cs(dot)wisc(dot)edu ) Associate Researcher Department of Computer Science University of Wisconsin-Madison http://www.cs.wisc.edu/(twiddle)thomas 1210 West Dayton Street Madison, WI 53706-1685 --
I get that when my initrd is messed up. I'll generally re-create it and things will be resolved. Also, you may try bumping up the ramdisk size in your pxelinux.cfg append ramdisk_size=20000 I create my initrd's with: zcat /tmp/initrd.img > /tmp/initrd.fs mkdir /mnt/initrd mount -o loop /tmp/initrd.fs /mnt/initrd make any changes...like putting in the new init and loader from anaconda-runtime umount /mnt/initrd cat /tmp/initrd.fs | gzip -9 > /tmp/initrd-new.img David Thompson wrote:>Hi all: > >I'm trying to rebuild the anaconda installer for Centos 4.0 (i386) to add some >RPMs and do some other things, and I've run into a problem. I've done lots of >anaconda rebuilds for Tao Linux 1.0, and I'm bringing those bits forward into >Centos 4.0. The all-knowing web hasn't turned up anything useful. It looks >like the PXE-loaded kernel unpacked and mounted the initrd OK, but then things >went awry (quickly). Anyone seen this on a PXE boot of an anaconda build? > ><snip> >RAMDISK: Compressed image found at block 0 >VFS: Mounted root (ext2 filesystem). >VFS: Cannot open root device "<NULL>" or unknown-block(3,2) >Please append a correct "root=" boot option >Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,2) > >Help or pointers to applicable docs very welcome. > >-- >Dave Thompson ( thomas(at)cs(dot)wisc(dot)edu ) > >Associate Researcher Department of Computer Science >University of Wisconsin-Madison http://www.cs.wisc.edu/(twiddle)thomas >1210 West Dayton Street >Madison, WI 53706-1685 >-- > >_______________________________________________ >CentOS mailing list >CentOS at centos.org >http://lists.centos.org/mailman/listinfo/centos > >-- Jay Hilliard Sr. Systems Administrator Disney Feature Animation (818) 460-9229
David Thompson wrote:> >Hi all: > >I'm trying to rebuild the anaconda installer for Centos 4.0 (i386) to add some > >RPMs and do some other things, and I've run into a problem. I've done lots of > >anaconda rebuilds for Tao Linux 1.0, and I'm bringing those bits forward into >Centos 4.0. The all-knowing web hasn't turned up anything useful. It looks >like the PXE-loaded kernel unpacked and mounted the initrd OK, but then things > >went awry (quickly). Anyone seen this on a PXE boot of an anaconda build? > ><snip> >RAMDISK: Compressed image found at block 0 >VFS: Mounted root (ext2 filesystem). >VFS: Cannot open root device "<NULL>" or unknown-block(3,2) >Please append a correct "root=" boot option >Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,2)Well, since no one replied to this I'll follow up my own post. It turns out that the 2.6.9-5.0.3.EL series of kernels has a bug in loop back mounting file systems: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=105595 (the bug is filed against fc3 but affects the original centos 4.0 kernels as well.) The bug prevents the initrd.img in anaconda from being populated, and everything goes kaplooey as soon as the PXE boot tries to do anything with it's initrd. It would also affect rebuilt ISO images. The fix is to upgrade the host running buildinstall to a 2.6.9-5.0.5.EL kernel, which has a fix for bug 105595. Then everything works just fine. -- Dave Thompson ( thomas(at)cs(dot)wisc(dot)edu ) Associate Researcher Department of Computer Science University of Wisconsin-Madison http://www.cs.wisc.edu/(twiddle)thomas 1210 West Dayton Street Madison, WI 53706-1685 --