[SOLVED] Slackware Linux Essentials question - Selecting a Kernel...

Robert.Thompson · 01-13-2011, 03:50 PM

Quote:

Originally Posted by 2handband

You're running the generic kernel now.

Thanks!

Just one question: How can you tell?

Robert.Thompson · 01-13-2011, 03:55 PM

Quote:

Originally Posted by gezley

Voila. You're good to go. Hope this helps.

Hi Gezley:

Thanks for all your time and effort - what a great post!

I will attempt this later this evening. It is 4:52pm here - shouldn't you be asleep? (please, don't tell me that you are!!!

)

Rob.

bgeddy · 01-13-2011, 04:00 PM

Quote:

Am I GENERIC or HUGE and how do I know?

Just run

Code:

cat /proc/cmdline

and this will tell you what boot image, root device and other parameters were passed during boot. Running lsmod will give you a fair idea, (once you are used to the output for generic versus huge), as the generic will have a lot more modules loaded however the first solution is safer when beginning.

onebuck · 01-13-2011, 04:08 PM

Hi,

Quote:

Originally Posted by Robert.Thompson

I got some msg's:

Code:

bash-4.1# lilo
Warning: LBA32 addressing assumed
Warning: Unable to determine video adapter in use in the present system.
Warning: Video adapter does not support VESA BIOS extensions needed for
  display of 256 colors.  Boot loader will fall back to TEXT only operation.
Added Windows *
Added Linux_G
Added Linux
3 warnings were issued.
bash-4.1#

Should I still re-boot or have I screwed something up?

If it matters, I am using a Lenovo X61 laptop.

Thanks,

The first warning can be rid of by using the 'lba32' in the global section of your '/etc/lilo.conf'.

Second, third warning by use of the 'vga=normal' in '/etc/lilo.conf'.
Do the following with the '/etc/lilo.conf';

Quote:

~#vi lilo.conf #edit lilo.conf to make the changes

~#lilo -v -t -b /dev/your_device #sda, hda this will only test
~#lilo -v -b /dev/your_device #this will write to your boot

First line is just edit of the '/etc/lilo.conf' file. The next will test (-t) the '/etc/lilo.conf'. If you get a clean output then perform the last by removing the '-t' and running the command. I do suggest that you 'man command' things to understand fully.

When you are working on the kernel, be sure to keep a working kernel stanza within the '/etc/lilo.conf' to allow you to recover when needed.

Robert.Thompson · 01-13-2011, 04:11 PM

Quote:

Originally Posted by bgeddy

Just run

Code:

cat /proc/cmdline

and this will tell you what boot image, root device and other parameters were passed during boot. Running lsmod will give you a fair idea, (once you are used to the output for generic versus huge), as the generic will have a lot more modules loaded however the first solution is safer when beginning.

Thank you, I can now see that I am a GENERIC Slacker!

Gerard Lally · 01-13-2011, 04:20 PM

Quote:

Originally Posted by Robert.Thompson

It is 4:52pm here - shouldn't you be asleep? (please, don't tell me that you are!!!

)

No! It's just 10:18 here! But don't tell mammy I'm still up!

chrisretusn · 01-13-2011, 04:55 PM

Quote:

Originally Posted by Robert.Thompson

I forgot that I was waiting for some advice and re-boot and selected Linux_G; here is what I see now:

Code:

bash-4.1# ls -l /boot
total 24360
lrwxrwxrwx  1 root root      37 2011-01-06 07:57 README.initrd -> /usr/doc/mkinitrd-1.4.5/README.initrd
lrwxrwxrwx  1 root root      32 2011-01-06 07:56 System.map -> System.map-huge-smp-2.6.33.4-smp
-rw-r--r--  1 root root 1282716 2010-05-13 01:00 System.map-generic-2.6.33.4
-rw-r--r--  1 root root 1322225 2010-05-12 22:41 System.map-generic-smp-2.6.33.4-smp
-rw-r--r--  1 root root 2041855 2010-05-13 01:28 System.map-huge-2.6.33.4
-rw-r--r--  1 root root 2086543 2010-05-12 23:48 System.map-huge-smp-2.6.33.4-smp
-rw-r--r--  1 root root     512 2011-01-06 08:14 boot.0800
-rw-r--r--  1 root root     512 2011-01-06 08:14 boot.0810
-rw-r--r--  1 root root     209 2011-01-06 08:14 boot_message.txt
lrwxrwxrwx  1 root root      28 2011-01-06 07:56 config -> config-huge-smp-2.6.33.4-smp
-rw-r--r--  1 root root  108261 2010-05-13 01:00 config-generic-2.6.33.4
-rw-r--r--  1 root root  108627 2010-05-12 22:41 config-generic-smp-2.6.33.4-smp
-rw-r--r--  1 root root  108235 2010-05-13 01:28 config-huge-2.6.33.4
-rw-r--r--  1 root root  108601 2010-05-12 23:48 config-huge-smp-2.6.33.4-smp
-rw-r--r--  1 root root    5040 2010-02-16 15:44 diag1.img
drwxr-xr-x 11 root root    4096 2011-01-13 14:59 initrd-tree
-rw-r--r--  1 root root 1707397 2011-01-13 14:59 initrd.gz
-rw-------  1 root root  131072 2011-01-13 15:53 map
-rw-r--r--  1 root root   14174 2010-02-14 20:57 slack.bmp
lrwxrwxrwx  1 root root      29 2011-01-06 07:56 vmlinuz -> vmlinuz-huge-smp-2.6.33.4-smp
-rw-r--r--  1 root root 2545840 2010-05-13 01:00 vmlinuz-generic-2.6.33.4
-rw-r--r--  1 root root 2662400 2010-05-12 22:41 vmlinuz-generic-smp-2.6.33.4-smp
-rw-r--r--  1 root root 5243760 2010-05-13 01:28 vmlinuz-huge-2.6.33.4
-rw-r--r--  1 root root 5421536 2010-05-12 23:48 vmlinuz-huge-smp-2.6.33.4-smp
bash-4.1#

Am I GENERIC or HUGE and how do I know?

Thanks,

You are running huge. How to tell? See the above I have highlighted in red. System.map, config and vmlinuz point to huge-smp-2.6.33.4-smp or the huge kernel. How to switch to the generic kernel? Remove the existing links and then link to the generic-smp-2.6.33.4-smp kernel.

# cd /root/
# rm System.map
# ln -s System.map-generic-smp-2.6.33.4-smp System.map
# rm config
# ln -s config-generic-smp-2.6.33.4-smp config
# rm vmlinuz
# ln -s vmlinuz-generic-smp-2.6.33.4-smp vmlinuz

Just to make sure all is well also run this to make sure you have initrd setup.

# mkinitrd -c -k 2.6.33.4-smp [-m <needed modules here>]

Your lilo.conf should have an 'initrd = /boot/initrd.gz' statement in it.

Last run lilo and reboot.

2handband · 01-13-2011, 07:00 PM

I've modified the tutorial in question to clear up the confusion about running lilo. Sorry, Robert.

T3slider · 01-13-2011, 08:16 PM

Quote:

Originally Posted by chrisretusn

You are running huge. How to tell? See the above I have highlighted in red. System.map, config and vmlinuz point to huge-smp-2.6.33.4-smp or the huge kernel. How to switch to the generic kernel? Remove the existing links and then link to the generic-smp-2.6.33.4-smp kernel.

# cd /root/
# rm System.map
# ln -s System.map-generic-smp-2.6.33.4-smp System.map
# rm config
# ln -s config-generic-smp-2.6.33.4-smp config
# rm vmlinuz
# ln -s vmlinuz-generic-smp-2.6.33.4-smp vmlinuz

Just to make sure all is well also run this to make sure you have initrd setup.

# mkinitrd -c -k 2.6.33.4-smp [-m <needed modules here>]

Your lilo.conf should have an 'initrd = /boot/initrd.gz' statement in it.

Last run lilo and reboot.

The only important symlink there is System.map --> System.map-generic-smp-2.6.33.4-smp, and I'm not 100% sure whether that's needed either.

Code:

diff <(zcat /proc/config.gz) /boot/config-generic-smp-2.6.33.4-smp &>/dev/null && echo true || echo false

That would tell you what kernel you are actually running -- if it outputs true, then you're running the generic kernel. False means you are probably running the huge kernel (though you could change the path to /boot/config-huge-smp-2.6.33.4-smp and expect an output of true to verify that). The config-* files are really just for your benefit -- the kernel itself doesn't care about them (it stores its config file internally accessible via /proc/config.gz, and even if it's compiled without that option I don't believe the kernel uses the config file for anything post-compilation). The vmlinuz symlink is only necessary if you don't explicitly name the vmlinuz-generic-smp-2.6.33.4-smp file in lilo.conf (ie if you just use /boot/vmlinuz). So the presence of that symlink is not indicative of which kernel you are actually running. The System.map file is trickier...it is used to lookup symbol information and is mostly valuable for kernel oops debugging, and your system would run perfectly fine with an incorrect System.map file (though if you get a kernel oops you'd get some bad results). I've been looking for proper information on this, but my searches have come up empty. klogd looks for /boot/System.map-$(uname -r) first -- but because Slackware's System.map files have the generic/huge identifier added, I'm not sure if klogd actually grabs the right one. I'm running the generic kernel on Slackware64-13.1 with System.map still pointing to the huge kernel's System.map file, but there are no messages about the wrong System.map file being used in any of my logs. See here for more information, but alas it does not provide the information I wanted (neither does `man klogd`). Using strace alongside klogd doesn't give me any valuable information either.

Anyway, the System.map symlink couldn't hurt, so you may want to change that -- but if you want to be 100% positive that you are running the generic-smp kernel, use the first command I mentioned.

Robert.Thompson · 01-14-2011, 06:54 AM

Quote:

Originally Posted by T3slider

The only important symlink there is System.map --> System.map-generic-smp-2.6.33.4-smp, and I'm not 100% sure whether that's needed either.

Code:

diff <(zcat /proc/config.gz) /boot/config-generic-smp-2.6.33.4-smp &>/dev/null && echo true || echo false

That would tell you what kernel you are actually running -- if it outputs true, then you're running the generic kernel. False means you are probably running the huge kernel (though you could change the path to /boot/config-huge-smp-2.6.33.4-smp and expect an output of true to verify that). The config-* files are really just for your benefit -- the kernel itself doesn't care about them (it stores its config file internally accessible via /proc/config.gz, and even if it's compiled without that option I don't believe the kernel uses the config file for anything post-compilation). The vmlinuz symlink is only necessary if you don't explicitly name the vmlinuz-generic-smp-2.6.33.4-smp file in lilo.conf (ie if you just use /boot/vmlinuz). So the presence of that symlink is not indicative of which kernel you are actually running. The System.map file is trickier...it is used to lookup symbol information and is mostly valuable for kernel oops debugging, and your system would run perfectly fine with an incorrect System.map file (though if you get a kernel oops you'd get some bad results). I've been looking for proper information on this, but my searches have come up empty. klogd looks for /boot/System.map-$(uname -r) first -- but because Slackware's System.map files have the generic/huge identifier added, I'm not sure if klogd actually grabs the right one. I'm running the generic kernel on Slackware64-13.1 with System.map still pointing to the huge kernel's System.map file, but there are no messages about the wrong System.map file being used in any of my logs. See here for more information, but alas it does not provide the information I wanted (neither does `man klogd`). Using strace alongside klogd doesn't give me any valuable information either.

Anyway, the System.map symlink couldn't hurt, so you may want to change that -- but if you want to be 100% positive that you are running the generic-smp kernel, use the first command I mentioned.

Thanks! It's TRUE, I am GENERIC.

Here is my output:

Code:

bash-4.1# cat /proc/cmdline
BOOT_IMAGE=Linux_G ro root=808 vt.default_utf8=0

bash-4.1# diff <(zcat /proc/config.gz) /boot/config-generic-smp-2.6.33.4-smp &>/dev/null && echo true || echo false
true
bash-4.1#

Robert.Thompson · 01-14-2011, 07:19 AM

Quote:

Originally Posted by 2handband

You're running the generic kernel now.

Hi Gene:

Pls forgive me for being persistent about this but I 'need' to know how you knew that my system was GENERIC...

Did you determine that from my 'ls -l /boot' output above, and if so, 'how' do you know?
or,
Did you know that if I followed your tutorial correctly, that I would be GENERIC?

Off-topic comment:

Thank you for your great tutorials - ever since I discovered them, I refer to them all the time. I am certain that your efforts are making 'that fog called linux' lift for many readers!

2handband · 01-14-2011, 07:23 AM

I knew because you selected Linux_G at your prompt screen, and if you followed my instructions that can only be the generic kernel. I've gone through this process enough times myself to have confidence in it.

Glad you like the tutorials. I'll have another one up soon on file permissions.

Robert.Thompson · 01-14-2011, 08:01 AM

Quote:

Originally Posted by 2handband

I knew because you selected Linux_G at your prompt screen, and if you followed my instructions that can only be the generic kernel. I've gone through this process enough times myself to have confidence in it.

Glad you like the tutorials. I'll have another one up soon on file permissions.

Thanks! I needed that!

Robert.Thompson · 01-14-2011, 08:15 AM

Quote:

Originally Posted by onebuck

Hi,

The first warning can be rid of by using the 'lba32' in the global section of your '/etc/lilo.conf'.

Second, third warning by use of the 'vga=normal' in '/etc/lilo.conf'.
Do the following with the '/etc/lilo.conf';

First line is just edit of the '/etc/lilo.conf' file. The next will test (-t) the '/etc/lilo.conf'. If you get a clean output then perform the last by removing the '-t' and running the command. I do suggest that you 'man command' things to understand fully.

When you are working on the kernel, be sure to keep a working kernel stanza within the '/etc/lilo.conf' to allow you to recover when needed.

Hi Gary:

Here is my output now:

Code:

bash-4.1# lilo -v -t -b /dev/sda8
LILO version 22.8 (test mode), Copyright (C) 1992-1998 Werner Almesberger
Development beyond version 21 Copyright (C) 1999-2006 John Coffman
Released 19-Feb-2007 and compiled at 14:44:48 on Feb 16 2010

Warning: Ignoring entry 'boot'
Reading boot sector from /dev/sda8
Using BITMAP secondary loader
Calling map_insert_data
Mapping bitmap file /boot/slack.bmp
Calling map_insert_file

Boot other: /dev/sda1, on /dev/sda, loader CHAIN
Added Windows *

Boot image: /boot/vmlinuz-generic-smp-2.6.33.4-smp
Mapping RAM disk /boot/initrd.gz
Added Linux_Generic

Boot image: /boot/vmlinuz -> vmlinuz-huge-smp-2.6.33.4-smp
Added Linux

The boot sector and the map file have *NOT* been altered.
One warning was issued.
bash-4.1#

Only one warning.

Here is my etc/lilo.conf:

Code:

# LILO configuration file
# generated by 'liloconfig'
#
# Start LILO global section
lba32
# Append any additional kernel parameters:
append=" vt.default_utf8=0"
boot = /dev/sda

# Boot BMP Image.
# Bitmap in BMP format: 640x480x8
  bitmap = /boot/slack.bmp
# Menu colors (foreground, background, shadow, highlighted
# foreground, highlighted background, highlighted shadow):
  bmp-colors = 255,0,255,0,255,0
# Location of the option table: location x, location y, number of
# columns, lines per column (max 15), "spill" (this is how many
# entries must be in the first column before the next begins to
# be used.  We don't specify it here, as there's just one column.
  bmp-table = 60,6,1,16
# Timer location x, timer location y, foreground color,
# background color, shadow color.
  bmp-timer = 65,27,0,255

# Standard menu.
# Or, you can comment out the bitmap menu above and 
# use a boot message with the standard menu:
#message = /boot/boot_message.txt

# Wait until the timeout to boot (if commented out, boot the
# first entry immediately):
prompt
# Timeout before the first entry boots.
# This is given in tenths of a second, so 600 for every minute:
timeout = 100
# Override dangerous defaults that rewrite the partition table:
change-rules
  reset
# VESA framebuffer console @ 1024x768x256
# original vga = 773
  vga=normal
# Normal VGA console
# vga = normal
# VESA framebuffer console @ 1024x768x64k
# vga=791
# VESA framebuffer console @ 1024x768x32k
# vga=790
# VESA framebuffer console @ 1024x768x256
# vga=773
# VESA framebuffer console @ 800x600x64k
# vga=788
# VESA framebuffer console @ 800x600x32k
# vga=787
# VESA framebuffer console @ 800x600x256
# vga=771
# VESA framebuffer console @ 640x480x64k
# vga=785
# VESA framebuffer console @ 640x480x32k
# vga=784
# VESA framebuffer console @ 640x480x256
# vga=769
# End LILO global section
# Windows bootable partition config begins
other = /dev/sda1
  label = Windows
  table = /dev/sda
# Windows bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz-generic-smp-2.6.33.4-smp
  initrd = /boot/initrd.gz
  root = /dev/sda8
  label = Linux_Generic
  read-only
# Linux bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz
  root = /dev/sda8
  label = Linux
  read-only
# Linux bootable partition config ends

What is the problem that is causing the warning?

Thanks for you time with this,

onebuck · 01-14-2011, 08:27 AM

Hi,

By using the directive option '-b /dev/your_device' you are not using the 'boot=/dev/sda' within the '/etc/lilo.conf' thus the warning to ignore 'boot entry'.