Grub Error Collection [Part 5]

Message

slycordinator · Post by **slycordinator** » Fri Jun 02, 2006 8:50 pm

Rukie wrote:I setup everything with a * instead of module, and I still get the same error
Please specify valid root= and such.. any ideas?

Did you "mount /boot" before copying the kernel?

Drone4four · Post by **Drone4four** » Fri Jun 02, 2006 11:48 pm

slycordinator wrote:
Drone4four wrote:Thanks for answer. Am I supposed to copy the entire kernel directory? Wouldn't that be larger than 32MBs? Like I stated before, my /boot partition is hda1 and only 32MBs large. Do I just need a directory named "2.6.16"?
http://www.gentoo.org/doc/en/handbook/h ... t=1&chap=7

Look at section called "compiling and installing"

Thanks slycordinator, I just moved successfully the bZimage to my /boot as it explains in the handbook. My system boots, but now I have a different obstacle preventing me from using gentoo. I made a post here with the error message: http://forums.gentoo.org/viewtopic-t-467790.html

Rukie · Post by **Rukie** » Sat Jun 03, 2006 1:39 am

hehehe... yes, I'm sure I compiled the kernel, however.. I forgot to mount /dev/sda1 when I ran make install

then I got an error bout extfs and a bad superblock, realized I didn't set reiserfs in my fstab, fixed that, now it seems to load fine, added support for the ethernet card and that seems to work now...

However, I can't get the scsi cdrom to read, should I make a separate page for that? (er, I think I did already...)
like, there is no /dev/cdrom

as u can tell, i'm tired.. lol, thanks for the help

dae1 · Post by **dae1** » Sat Jun 03, 2006 7:12 am

I have something to contribute regarding Grub Error #15:

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Booting 'gentoo Linux'

root (hd0,1)
Filesystem type is ext2fs, partition type 0x83
kernel /boot/kernel-2.4.20 root=/dev/hda3 vga=792

Error 15: File not found
Press any key to continue...

This problem kept coming up for me all week and I had gone through the forums and found a lot of answers that didn't help me. Well, I recall in the Grub FAQ that one way was to compile grub in /boot/boot. I found a workaround that.

This is the following steps I did to fix this particular error:
1. Use the install CD and redo the mount procedures especially boot.
2. goto /boot, $> cd /boot
3. Make another boot directory, $> mkdir boot .
4. Copy the kernel or move (whichever you prefer), into the newly made boot directory. cp kernel /boot/boot.
5. Unmount and reboot.

After that, it worked fine for me. It solved my VFS no root= or (hd0,0) found error.

This setup works for a dual boot with windows set at (hd0,0) and gentoo at (hd0,1; hd0,2; hd0,3)

Hope that helps.

Duminas · Post by **Duminas** » Sat Jun 03, 2006 7:34 pm

dae1 wrote:I have something to contribute regarding Grub Error #15:
Code: Select all
Booting 'gentoo Linux'

root (hd0,1)
Filesystem type is ext2fs, partition type 0x83
kernel /boot/kernel-2.4.20 root=/dev/hda3 vga=792

Error 15: File not found
Press any key to continue...
This problem kept coming up for me all week and I had gone through the forums and found a lot of answers that didn't help me. Well, I recall in the Grub FAQ that one way was to compile grub in /boot/boot. I found a workaround that.

This is the following steps I did to fix this particular error:
1. Use the install CD and redo the mount procedures especially boot.
2. goto /boot, $> cd /boot
3. Make another boot directory, $> mkdir boot .
4. Copy the kernel or move (whichever you prefer), into the newly made boot directory. cp kernel /boot/boot.
5. Unmount and reboot.

After that, it worked fine for me. It solved my VFS no root= or (hd0,0) found error.

This setup works for a dual boot with windows set at (hd0,0) and gentoo at (hd0,1; hd0,2; hd0,3)

Hope that helps.

Why not just symlink it?

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# cd /boot
# ln -s ./ boot

That fixed the same problem for me awhile back.

airmig · Post by **airmig** » Sat Jun 03, 2006 8:30 pm

Is it possible to have 1 partition for everything. - dont ask why but how how would the fstab and grub config would look like?

I get it to boot but I cant get it to mount root. It says root=/dev/sda1 not working.

Post by **NeddySeagoon** » Sat Jun 03, 2006 8:58 pm

Duminas,

/boot is supposed to be symlinked to itself. It allows the same grub.conf to work regardless if /boot is a real partition or not.

hjkelly · Post by **hjkelly** » Mon Jun 05, 2006 12:46 pm

I've installed Gentoo on a new computer with one SATA drive and two IDE drives. At first, I tried to install Gentoo on the SATA, but I got an "Error 15 - File not found" error when I restarted. I figured it was a problem with SATA (or me not understanding it), so I did a fresh install on the primary IDE (hda), and now I'm getting the same error. I've looked at a lot of stuff about Error 15 in Grub, and I've done at least ten Gentoo installs in my day, but this has my mind boggled. I've double-checked that the drives and locations I'm using are right (I think), but nothing has worked. Here's some stuff that might be useful:

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# ls /boot
total 2635
-rw-r--r--  1 root root  763030 Jun  4 23:33 System.map
lrwxrwxrwx  1 root root       1 Jun  4 13:53 boot -> .
-rw-r--r--  1 root root   33002 Jun  4 23:34 config-2.6.16.9
drwxr-xr-x  2 root root    1024 Jun  5 00:12 grub
-rw-r--r--  1 root root 1872267 Jun  4 23:33 kernel-2.6.16.9
drwx------  2 root root   12288 Jun  4 13:23 lost+found

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# cat /boot/grub/grub.conf
default 0
timeout 10

title Gentoo Linux 2.6.16.9
root (hd2,0)
kernel /boot/kernel-2.6.16.9 root=/dev/hda4

title Windows XP
map (hd0) (hd2)
map (hd2) (hd0)
rootnoverify (hd2,1)
makeactive
chainloader +1

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# cat /etc/fstab
/dev/hda1               /boot           ext3            noauto,noatime  1 2
/dev/hda4               /               reiserfs        noatime         0 1
/dev/hda3               none            swap            sw              0 0
/dev/hdd                /mnt/cdrom      iso9660         noauto,ro       0 0

proc                    /proc           proc            defaults        0 0

shm                     /dev/shm        tmpfs           nodev,nosuid,noexec 0 0

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# fdisk /dev/hda -> p
   Device Boot      Start         End      Blocks   Id  System
   /dev/hda1   *           1          13      104391   83  Linux
   /dev/hda2              14        2446    19543072+   c  W95 FAT32 (LBA)
   /dev/hda3            2447        2690     1959930   82  Linux swap / Solaris
   /dev/hda4            2691        9964    58428405   83  Linux

One thing I was unsure about was the Grub notation for my drives since they're merging both hdX and sdX. I have hda (hd2), hdb (hd1), and sda (hd0). That order is exactly the opposite of what I would've guessed, so I'm glad I was able to set things straight using the root(hdX,Y) command in Grub to figure out their types.

Also, I don't think the map thing worked on the Windows section of Grub, because that won't start either.

Any help would be greatly appreciated!

PsychoticRetina · Post by **PsychoticRetina** » Mon Jun 05, 2006 12:57 pm

hjkelly wrote:title Gentoo Linux 2.6.16.9
root (hd2,0)
kernel /boot/kernel-2.6.16.9 root=/dev/hda4

replace with:

title Gentoo Linux 2.6.16.9
root (hd0,0)
kernel /boot/kernel-2.6.16.9 root=/dev/hda4

EDIT: you dont need to map anything, as your windows is on the master drive.

hjkelly · Post by **hjkelly** » Mon Jun 05, 2006 1:10 pm

Thanks so much, vesselin! I'm not sure what was happening there, because typing root (hd0,0) in the grub menu before gave me the reiserfs type, which was my SATA drive. Could anyone explain how this works?

PsychoticRetina · Post by **PsychoticRetina** » Mon Jun 05, 2006 1:16 pm

hjkelly wrote:Thanks so much, vesselin! I'm not sure what was happening there, because typing root (hd0,0) in the grub menu before gave me the reiserfs type, which was my SATA drive. Could anyone explain how this works?

what exactly do you have in mind by "it"?

hjkelly · Post by **hjkelly** » Mon Jun 05, 2006 1:32 pm

vesselin wrote:what exactly do you have in mind by "it"?

I'm just wondering if there was any way you knew hd0 would work instead of hd2 like I had, and why hd0 reported one hard drive's type and then booted to another. I guess Grub's drive/partition convention bothers me... that's all.

PsychoticRetina · Post by **PsychoticRetina** » Mon Jun 05, 2006 2:36 pm

root (hdx,y) *1
kernel /boot/kernel_name_here *2 root=/dev/hdx *3

*1 - tells grub which partition the KERNEL is located on. the kernel should be stored in the boot directory, which in your case is a separate partition (/dev/hda1). x=hdd location, counted from 0 (a=prim.master, b=prim.slave, c=sec.master, d=sec.slave) y=partition (0=first partiton, 1=second partiton, etc.) so, in your case, where the kernel is located on the first partition of the drive connected as primary master: root (hd0,0)
*2 - tells grub the exact name of the kernel.
*3 - grub doesnt care about the CONTENTS of the entry root=/dev/hdx (the contents being /dev/hdx), it only passes this to the kernel that it managed to boot using the 2 previous entries. the contents of this entry are only important to the kernel itself.
tip: you can replace the 2 first lines with a single one, so the final result becomes:

kernel (hd0,0)/kernel_name root=/dev/hdax

kasemodz · Post by **kasemodz** » Wed Jun 14, 2006 10:03 pm

Alright, in grub, I didn't make a boot partition just simply made a directory called boot in my / partiion. Well that parttion is hda4 so would my grub be (hd0,3)?

Post by **NeddySeagoon** » Wed Jun 14, 2006 10:55 pm

kasemodz,

Thats right and your splashimage, kernel, (and initrd) path will all be /boot/.... because root (hd0,3) does not point directly to where the files are, they are in the /boot directory.

pgreenwood · Post by **pgreenwood** » Thu Jun 15, 2006 3:19 pm

dae1 wrote:I have something to contribute regarding Grub Error #15:

I'm getting Error 15 and wondering:

/boot is on /dev/hde2
/ is on /dev/hde4

When I mount [only] /dev/hde4 a /boot directory is present and includes files other than what are in /dev/hde2.

/etc/fstab says /dev/hde2 is /boot

I think I should remove the contents of /boot on /dev/hde4 as this could be confusing GRUB. I'd leave the empty /boot mountpoint there.

/dev/hde2 does not have a symlink to /boot so I'd add this.

Apparently didn't have /dev/hde2 mounted when I copied bzImage over to /boot.

Your thoughts?

Thanks.

Pat

Post by **NeddySeagoon** » Thu Jun 15, 2006 3:41 pm

pgreenwood,

I think your diagnosis is correct.
Grub will not be confused. It uses the root (hdx,y) statement in your boot block withing grub.conf to find its own files and the files you need for booting.

Error 15 means that one of the files needed for booting, as given in your kernel or initrd statemenets is not found.
The names and locarions must be identical.

pgreenwood · Post by **pgreenwood** » Thu Jun 15, 2006 4:34 pm

Duminas wrote:
Why not just symlink it?
Code: Select all
# cd /boot
# ln -s ./ boot

Shouldn't it be:

Code: Select all

# cd /boot
# ln -s . /boot

or just

Code: Select all

# cd /boot
# ln -s .

?

Thanks.

Post by **NeddySeagoon** » Thu Jun 15, 2006 4:52 pm

pgreenwood,

The issue is that the boot files are on the wrong partition.

You could change the kernel and initrd entries in grub.conf but grub can only read a single filesystem, depending in the stage1.5 file installed, so /boot and / would need to be on the same filesystem type for that to work.

I don't think grub can follow symlinks across partitions, since nothing is mounted when grub loads the kernel.

lxg · Post by **lxg** » Thu Jun 15, 2006 5:30 pm

airmig wrote:Is it possible to have 1 partition for everything. - dont ask why but how how would the fstab and grub config would look like?

I get it to boot but I cant get it to mount root. It says root=/dev/sda1 not working.

It should be no problem. If it starts to boot, then it's ok. Just take a look into the handbook how disks and partitions are named in Grub and fstab.

The message that root=/dev/sda1 also could indicate a driver problem. If this is the case, you might need to rebuild your kernel with proper support for that device.

If you don't get further, please post the exact error message here.

pgreenwood · Post by **pgreenwood** » Thu Jun 15, 2006 5:57 pm

Thanks, NS.

Another GRUB resource comes by way of Steve Litt -- Mr. Troubleshooter. I often referred to his LyX studies and now find that he also tackled GRUB in his usual, thorough and straightforward manner. Enjoy.

Post by **NeddySeagoon** » Thu Jun 15, 2006 6:04 pm

lx0,

A single partition install is perfectly possible as long as your BIOS can read everything needed to boot.
The seperate /boot partiton at the start of the drive became essential when hard drives reached 528Mb and the BIOS could only read the start of the drive. The race between hard drives and BIOSs contines. Providied your BIOS can read the whole drive you won't have a problem.

You can even put swap in a file if you like, however, there is a swap speed penalty (when sapping is actually used) for that.

We need exact error messages to help you with your error

Code: Select all

root=/dev/sda1 not working.

is not exactly what the error was.

tired_geek · Post by **tired_geek** » Fri Jun 16, 2006 7:53 am

When updating my kernel, I broke my MBR. I left the previous kernel as an option to be safe, but must have botched the grub-install process because neither option boots (don't recall exact message, essense was that they couldn't find the kernel images). I imagine i pointed grub to the wrong partition for /boot.

My setup:

/ on /dev/sda6
/boot on /dev/sda3

I want to run grub-install, or related command sequence from a live cd so I can boot back into my installation. The basic sequence of commands, as I understand them, should be something like this:

Code: Select all

mount /mnt/sda6
mount /dev/sda3 /mnt/sda6/boot
chroot /mnt/sda6 /bin/bash
grub-install /dev/sda

When I do, grub replys:

/dev/sda does not have any corresponding BIOS drive.

I found a suggestion here: http://www.cyberciti.biz/faqs/2006/05/e ... ve-any.php that said I should run

Code: Select all

grub-install --recheck /dev/sda

That results in ...

Probing devices to guess BIOS drives. This may take a long time.
/sbin/grub-install: line 342: /dev/null: Permission denied
/dev/sda does not have any corresponding BIOS drive.

Running a "manual" grub install looks like this:

grub> root (hd0,2)

Error 21: Selected disk does not exist

grub>

Knoppix / # fdisk -l
cannot open /proc/partitions
Knoppix / #

I've tried combinations of chrooting, mount -t proc none /mnt/sda6/proc, grep -v rootfs /proc/mounts > /mnt/sda6/etc/mtab, and sometimes fdisk -l returns nothing in the chrooted environment. I'm somewhat confused about how being in a chrooted environment affects grub-install. The admonitions to mount proc, and copy proc/mounts to /etc/mtab in the chrooted environ seem unclear, but I'm getting pretty tired.

One final note: http://www.shahidhussain.com/wordpress/index.php?p=33 this guy mentions a hideous command sequence

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# # mkdir mounted
# # mount /dev/ide/host0/bus0/target0/lun0/part5 mounted
# # chroot mounted /bin/bash
# # grub-install /dev/hda

as a solution to the dev/null: Permission Denied problem. Besides having no clue -why- that should change anything, I've been unable to make it work.

getting either:

sh-3.00# mount /dev/ide/host0/bus0/target0/lun0/part2 /mnt/sda1
mount: special device /dev/ide/host0/bus0/target0/lun0/part2 does not exist
sh-3.00#

or

sh-3.00# mount /dev/sde/host0/bus0/target0/lun0/part2 /mnt/sda1
mount: special device /dev/sde/host0/bus0/target0/lun0/part2 does not exist
(a path prefix is not a directory)

sh-3.00#

Apologies if this is covering posts already described. I've googled and experimented for over 4 hours now, and briefly searched the gentoo forums before posting, but was frusturated by the broad results returned by the searches (and the inability to filter through these 14 pages of sticky-thread). There are many similar issues, but most seem to be solved by "chroot, grub-install." Why am I having so much trouble? I was hoping to use my laptop to do some work while traveling this weekend, but I'm beginning to despair.

Post by **NeddySeagoon** » Fri Jun 16, 2006 9:53 am

tired_geek,

NeddySeagoons' Chroot Rescue Guide

Welcome to Gentoo. A few things, since you provide so much information.

To get back into the chroot, the commands are

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mount -t <fstype> /dev/ROOT /mnt/gentoo
mount -t <fstype> /dev/BOOT /mnt/gentoo/boot
swapon /dev/...
mount -t proc /proc /mnt/gentoo/proc
mount -o bind /dev /mnt/gentoo/dev

You need to fill in the <fstype> for your filesystems and the actual devices for ROOT and BOOT.
IDE devices are knows as /dev/hd... SATA, SCSI and USB will be /dev/sd...
If you don't /boot on its own partition, omit that command - there is nothing to mount.

Now you have everything mounted you are ready to chroot with the commands

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chroot /mnt/gentoo /bin/bash
env-update
source /etc/profile

and if you want a pretty prompt

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export PS1="(chroot) $PS1"

Now, your own Gentoo system is running on the kernel provided by the liveCD.
Its like you had never left the chroot. You can continue the install or fix a broken one.

Note that grub is not like lilo. After grub is installed on the MBR and working, new kernels are added to grub.conf.
There is no need to reinstall grub. This is because grub reads grub.conf at boot time to know what to do but lilo loads a block list (it cannot read the filesystem at boot) which is created when /sbin/lilo is run.

Please try to suppy exact error messages, since it takes the guesswork out of what went wrong.

tired_geek · Post by **tired_geek** » Fri Jun 16, 2006 3:08 pm

Thanks Neddy. Your directions were spot-on. After a night's sleep I had the focus to go back through the gentoo install documentation and realised I missed the mount -o bind /dev /mnt/gentoo/dev step. No wonder grub couldn't do anything! So after following your chroot instructions and re- grub-install -ing, I realised I'd mistyped both linux kernel image names. Beware the - that resembles an _, especially at 4:00 am!

Interesting to learn I don't have to grub-install every time I change grub.conf. That might save a headache in the future.

Thanks!

Grub Error Collection [Part 5]

One partition

grub bootloader config

Re: One partition

Fixing grub from live cd (knoppix)

Thanks ned