Re: [lfs-support] Booting LFS Error Kernel Panic
On Thu, 2012-12-20 at 14:53 +, Richard Melville wrote: I think that was understood; when they said that it was stupid it was surely meant that there could be some confusion in the use of similar terms. Possibly, though if they'd understood it, you'd think they'd have mentioned the by-partuuid directory, instead of claiming that the gdisk tool was the only way of working out the partition UUID. Simon. It seems a little churlish to pick holes in what is essentially a good article, and, indeed, one that supplied the answer to a question on this list. Richard -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
Re: [lfs-support] Booting LFS Error Kernel Panic
On Sat, 2012-12-22 at 00:31 +, Richard Melville wrote: It seems a little churlish to pick holes in what is essentially a good article, and, indeed, one that supplied the answer to a question on this list. True. Well, suffice it to say that the /dev/disks symlink tree *does* support GPT partitions, and offers an easy way to identify partition UUIDs if you want to use them... Simon. signature.asc Description: This is a digitally signed message part -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
Re: [lfs-support] Booting LFS Error Kernel Panic
On Tue, 2012-12-18 at 11:19 +, Richard Melville wrote Would't using GPT instead of MBR be a viable alternative? Nope. GPT assigns UUIDs to the partitions, but that's all - the kernel still deals only with traditional device names (sda1, sda2, etc). The initramfs is still needed to work out which device to mount when given a UUID. The main advantage of the GPT UUIDs in this respect is that because they're on the partition itself rather than the filesystem, they remain constant when reformatting the partition (unlike fs-level UUIDs), and if disks are added and removed from the machine (unlike traditional device names). Simon. signature.asc Description: This is a digitally signed message part -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
Re: [lfs-support] Booting LFS Error Kernel Panic
Now it would be nice for it to work using UUIDs so the booting can be independent of host system. You need to use an initrd of that. See BLFS. -- Bruce Would't using GPT instead of MBR be a viable alternative? Richard -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
Re: [lfs-support] Booting LFS Error Kernel Panic
On 18/12/12 01:24, Alexander Spitzer wrote:
Hello all,
I am having a hard time booting my LFS system, which is on a USB
drive. I installed grub on /dev/sdc (the usb relative to the host) and
the bios successfully finds GRUB. After around 2.3 seconds, the boot
process hangs after printing what I believe to be a trace call.
Interestingly, one time when I booted the trace call was short enough
for me to write down the error which I can't normally see due to the
length of the trace prints. Here is the error:
Kernel panic-not syncing: VFS: Unable to mount root fs on unknown
block(0,0)
What exactly does unknown block(0,0) mean?
The problem appears to be that the kernel can't find the root file
system. How can that be a problem, if the kernel, which is ON the root
file system, was found and ran?
Here is the grub.cfg file:
# Begin /boot/grub/grub.cfg
set default=0
set timeout=5
insmod ext2
set root=(hd0,1)
menuentry GNU/Linux, Linux 3.7-lfs-SVN-20121212 {
linux /boot/vmlinuz-3.7-lfs-SVN-20121212 root=/dev/sda1 ro
}
I believe the USB is always sda because to boot I do a manual boot
override and select USB from the BIOS menu. The grub command line also
confirms this.
Searching online, there were some suggestions that the kernel was
compiled without support for necessary file systems and hardware. I
check my config file for the kernel and found all the important
options to be set to yes (USB_mass_storage, ext3 filesystem, USB UHCI,
USB OHCI, and several scsi ones). There are however many USB options
that are not set. Are there any specific ones that should be set for
the kernel to load the root filesystem?
Also, I've tried unsuccessfully to read more of the boot output by two
methods: increasing the resolution and scrolling back. The scroll back
buffer is set to yes in the kernel config yet shift page down and
shift page up do nothing. Also, vga=791 is deprecated and I haven't
been able to get any effect by using set vgxpayload=1024x728.
How can I read the boot print outputs without a high speed camera?
Thanks,
Alex
Hi
This is my grub.cfg which is on usb drive that works
# Begin /boot/grub/grub.cfg
set default=0
set timeout=5
insmod ext2
set root=(hd0,1)
menuentry Planet-Spike7 {
linux /boot/vmlinuz-3.2-lfs-7.0 root=/dev/sdc1 rootdelay=5 ro
}
the rootdelay seems to be the cure tou might want to try 10 instaed of 5
then adjust it.
It takes time for the usb to recognised
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[lfs-support] Booting LFS Error Kernel Panic
Hello all,
I am having a hard time booting my LFS system, which is on a USB drive. I
installed grub on /dev/sdc (the usb relative to the host) and the bios
successfully finds GRUB. After around 2.3 seconds, the boot process hangs
after printing what I believe to be a trace call. Interestingly, one time
when I booted the trace call was short enough for me to write down the
error which I can't normally see due to the length of the trace prints.
Here is the error:
Kernel panic-not syncing: VFS: Unable to mount root fs on unknown block(0,0)
What exactly does unknown block(0,0) mean?
The problem appears to be that the kernel can't find the root file system.
How can that be a problem, if the kernel, which is ON the root file system,
was found and ran?
Here is the grub.cfg file:
# Begin /boot/grub/grub.cfg
set default=0
set timeout=5
insmod ext2
set root=(hd0,1)
menuentry GNU/Linux, Linux 3.7-lfs-SVN-20121212 {
linux /boot/vmlinuz-3.7-lfs-SVN-20121212 root=/dev/sda1 ro
}
I believe the USB is always sda because to boot I do a manual boot override
and select USB from the BIOS menu. The grub command line also confirms this.
Searching online, there were some suggestions that the kernel was compiled
without support for necessary file systems and hardware. I check my config
file for the kernel and found all the important options to be set to yes
(USB_mass_storage, ext3 filesystem, USB UHCI, USB OHCI, and several scsi
ones). There are however many USB options that are not set. Are there any
specific ones that should be set for the kernel to load the root filesystem?
Also, I've tried unsuccessfully to read more of the boot output by two
methods: increasing the resolution and scrolling back. The scroll back
buffer is set to yes in the kernel config yet shift page down and shift
page up do nothing. Also, vga=791 is deprecated and I haven't been able to
get any effect by using set vgxpayload=1024x728.
How can I read the boot print outputs without a high speed camera?
Thanks,
Alex
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Re: [lfs-support] Booting LFS Error Kernel Panic
I got it to work! Turns out that the root file system changes to /dev/sdc1
after all the harddisks are found so changing the line root=/dev/sda1 to
root=/dev/sdc1 and adding a rootdelay successfully booted the system!
Now it would be nice for it to work using UUIDs so the booting can
be independent of host system.
Also, the scrollback buffer does work just not when the kernel has crashed.
I am sorry for the long kind of useless post but if anyone has anything to
add please feel free.
On Mon, Dec 17, 2012 at 5:24 PM, Alexander Spitzer aes...@cornell.eduwrote:
Hello all,
I am having a hard time booting my LFS system, which is on a USB drive. I
installed grub on /dev/sdc (the usb relative to the host) and the bios
successfully finds GRUB. After around 2.3 seconds, the boot process hangs
after printing what I believe to be a trace call. Interestingly, one time
when I booted the trace call was short enough for me to write down the
error which I can't normally see due to the length of the trace prints.
Here is the error:
Kernel panic-not syncing: VFS: Unable to mount root fs on unknown
block(0,0)
What exactly does unknown block(0,0) mean?
The problem appears to be that the kernel can't find the root file system.
How can that be a problem, if the kernel, which is ON the root file system,
was found and ran?
Here is the grub.cfg file:
# Begin /boot/grub/grub.cfg
set default=0
set timeout=5
insmod ext2
set root=(hd0,1)
menuentry GNU/Linux, Linux 3.7-lfs-SVN-20121212 {
linux /boot/vmlinuz-3.7-lfs-SVN-20121212 root=/dev/sda1 ro
}
I believe the USB is always sda because to boot I do a manual boot
override and select USB from the BIOS menu. The grub command line also
confirms this.
Searching online, there were some suggestions that the kernel was compiled
without support for necessary file systems and hardware. I check my config
file for the kernel and found all the important options to be set to yes
(USB_mass_storage, ext3 filesystem, USB UHCI, USB OHCI, and several scsi
ones). There are however many USB options that are not set. Are there any
specific ones that should be set for the kernel to load the root filesystem?
Also, I've tried unsuccessfully to read more of the boot output by two
methods: increasing the resolution and scrolling back. The scroll back
buffer is set to yes in the kernel config yet shift page down and shift
page up do nothing. Also, vga=791 is deprecated and I haven't been able to
get any effect by using set vgxpayload=1024x728.
How can I read the boot print outputs without a high speed camera?
Thanks,
Alex
--
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FAQ: http://www.linuxfromscratch.org/lfs/faq.html
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Re: [lfs-support] Booting LFS Error Kernel Panic
Alexander Spitzer wrote: I got it to work! Turns out that the root file system changes to /dev/sdc1 after all the harddisks are found so changing the line root=/dev/sda1 to root=/dev/sdc1 and adding a rootdelay successfully booted the system! Now it would be nice for it to work using UUIDs so the booting can be independent of host system. You need to use an initrd of that. See BLFS. -- Bruce -- http://linuxfromscratch.org/mailman/listinfo/lfs-support FAQ: http://www.linuxfromscratch.org/lfs/faq.html Unsubscribe: See the above information page
