Difference between revisions of "Troubleshooting"

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(My kernel won't boot! How do I rebuild it?)
 
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== Installation issues ==
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{{Buildfromscratch}}
  
  
== Boot issues ==
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== Installation issues ==
 +
 
 
=== My kernel won't boot! How do I rebuild it? ===
 
=== My kernel won't boot! How do I rebuild it? ===
 +
 
If you broke your kernel and can no longer reboot, either by removing a necessary feature for booting or maybe making it a [M] module instead of [*] built-in, you will need to re-enter your installed environment by using the original CRUX installation iso ([[Troubleshooting#My_kernel_won.27t_boot.21_How_do_I_rebuild_it.3F|rescue procedure]]).  
 
If you broke your kernel and can no longer reboot, either by removing a necessary feature for booting or maybe making it a [M] module instead of [*] built-in, you will need to re-enter your installed environment by using the original CRUX installation iso ([[Troubleshooting#My_kernel_won.27t_boot.21_How_do_I_rebuild_it.3F|rescue procedure]]).  
 
# Remount your CRUX Linux iso
 
# Remount your CRUX Linux iso
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</nowiki>
 
</nowiki>
 
Finally, unmount the iso and reboot the system.
 
Finally, unmount the iso and reboot the system.
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== Boot issues ==
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 +
=== General boot issue ===
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Many problems can occur at boot-time, but may not have sufficient information to diagnose and fix. You can get additional information by removing the <tt>'quiet'</tt> word from <tt>/etc/lilo.conf</tt>. This will have Linux produce all initialization output which should make debugging much easier. Also, you can check the files in <tt>/var/log</tt>, such as <tt>boot</tt>, <tt>messages</tt>, etc. which will give additional insight to boot problems.
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=== Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1) ===
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This issue can arise from one of two reasons:
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# The boot partition's filesystem was not built into the kernel (e.g., EXT4/ReiserFS)
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# The kernel does not have the appropriate SATA/hard disk controller drivers in order to recognize the boot partition
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To fix this, follow the [[Troubleshooting#My_kernel_won.27t_boot.21_How_do_I_rebuild_it.3F|rescue boot]] instructions.
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[[File:kernel_panic.png|thumb|none|400px|Kernel panic - no syncing]]
  
 
=== "error: couldn't mount because of unsupported optional features (240/244)" ===
 
=== "error: couldn't mount because of unsupported optional features (240/244)" ===
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* If you have already compiled and copied the kernel as /boot/vmlinuz, check two places:
 
* If you have already compiled and copied the kernel as /boot/vmlinuz, check two places:
 
** After copying <tt>vmlinuz</tt> and <tt>System.map</tt> to <tt>/boot</tt>, did you run <tt>lilo</tt>?
 
** After copying <tt>vmlinuz</tt> and <tt>System.map</tt> to <tt>/boot</tt>, did you run <tt>lilo</tt>?
*** Running <tt>lilo</tt> should report no errors.
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*** Running <tt>lilo</tt> should have reported no errors. To fix this, follow the [[Troubleshooting#My_kernel_won.27t_boot.21_How_do_I_rebuild_it.3F|rescue boot]] instructions.
** In <tt>fdisk</t>, type <tt>p <enter></tt> to see the master boot record. Is partition one marked with an asterisk (*) as bootable?
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** In <tt>fdisk</tt>, type <tt>p <enter></tt> to see the master boot record. Is partition one marked with an asterisk (*) as bootable?
 
*** If not, mark it as bootable with:<br>
 
*** If not, mark it as bootable with:<br>
 
  <nowiki>
 
  <nowiki>
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== Ports issues ==
 
== Ports issues ==
  
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<nowiki>
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=======> ERROR: Footprint mismatch found:
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MISSING -rwxr-xr-x root/root usr/lib/python2.7/lib-dynload/dl.so
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MISSING -rwxr-xr-x root/root usr/lib/python2.7/lib-dynload/imageop.so
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Building /usr/ports/ppc/opt/python#2.7.2-1.pkg.tar.gz' failed.
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</nowiki>
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This issue must be fixed at the port maintainers end, updating the port to expect different/compatible-old versions of libraries. To get through this issue, you may suppress footprint mismatch errors and continue through. More accurately, it ignores the footprint check step.
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 +
# <tt>vi /etc/pkgmk.conf</tt>
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# Uncomment and adjust the line: <tt>PKGMK_IGNORE_FOOTPRINT="yes"</tt>
  
 
== Scripts issues ==
 
== Scripts issues ==
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# [[Top|sshd]] (SSH background daemon process) not running  
 
# [[Top|sshd]] (SSH background daemon process) not running  
 
# [[iptables]] (firewall) prohibiting connection
 
# [[iptables]] (firewall) prohibiting connection
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=== Issued an IP address but unable to connect to internet/ping destination ===
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If <tt>ifconfig</tt> reports an IP address issued to your interface, but you are unable to access the internet, there are a few places to check. Such behavior like this dropping 100% packets during ping.
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# <tt>iptables -F</tt> - flushes any existing IP tables filtering rules to allow all traffic.
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# [[Installing crux#Configure_network_routing|Network routing]] (ethernet) not set up. Check specifically the <tt>route add default via</tt> line.
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# [[Wireless_Networking#Auto-joining_network_with_DHCP|Wireless routing]] (wifi) improperly set up. Check specifically the <tt>route add default gw</tt> line.
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 +
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[[Category:Buildfromscratch]]

Latest revision as of 00:55, 2 October 2011


Contents

Installation issues

My kernel won't boot! How do I rebuild it?

If you broke your kernel and can no longer reboot, either by removing a necessary feature for booting or maybe making it a [M] module instead of [*] built-in, you will need to re-enter your installed environment by using the original CRUX installation iso (rescue procedure).

  1. Remount your CRUX Linux iso
  2. Reboot your system and boot from the ISO
  3. Type in CRUX and press enter
  4. Log in as root
  5. Type in the following commands:
# mount /dev/sda1 /mnt
# setup-chroot
# cd /usr/src/linux-2.6.25.6
# make menuconfig
# make all
# make modules_install
# cp arch/x86/boot/bzImage /boot/vmlinuz
# cp System.map /boot/
# lilo
# shutdown now

Finally, unmount the iso and reboot the system.

Boot issues

General boot issue

Many problems can occur at boot-time, but may not have sufficient information to diagnose and fix. You can get additional information by removing the 'quiet' word from /etc/lilo.conf. This will have Linux produce all initialization output which should make debugging much easier. Also, you can check the files in /var/log, such as boot, messages, etc. which will give additional insight to boot problems.

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,1)

This issue can arise from one of two reasons:

  1. The boot partition's filesystem was not built into the kernel (e.g., EXT4/ReiserFS)
  2. The kernel does not have the appropriate SATA/hard disk controller drivers in order to recognize the boot partition

To fix this, follow the rescue boot instructions.

Kernel panic - no syncing

"error: couldn't mount because of unsupported optional features (240/244)"

This is more of a warning than an error. It occurs because the boot sequence attempts to read the boot partition with EXT3/EXT2, which is not the actual filesystem. It then continues by attempting ReiserFS/EXT4 and successfully locates the kernel. Since it gives the impression of an unclean installation, you can suppress these errors most easily by removing EXT3/EXT2 support in the kernel--neither filesystems will be used in MineOS. Otherwise, you can simply ignore it.

error: couldn't mount

"FATAL: No bootable medium found! System halted."

Depending on what steps you have completed, this can mean different things.

  • If are starting from the very, very beginning, it simply means the CRUX Linux iso is not mounted
  • If you have already compiled and copied the kernel as /boot/vmlinuz, check two places:
    • After copying vmlinuz and System.map to /boot, did you run lilo?
      • Running lilo should have reported no errors. To fix this, follow the rescue boot instructions.
    • In fdisk, type p <enter> to see the master boot record. Is partition one marked with an asterisk (*) as bootable?
      • If not, mark it as bootable with:
a <enter>
1 <enter>
p <enter> (verify bootable flag set)
w <enter>

Ports issues

=======> ERROR: Footprint mismatch found:
MISSING -rwxr-xr-x root/root usr/lib/python2.7/lib-dynload/dl.so
MISSING -rwxr-xr-x root/root usr/lib/python2.7/lib-dynload/imageop.so
Building /usr/ports/ppc/opt/python#2.7.2-1.pkg.tar.gz' failed.

This issue must be fixed at the port maintainers end, updating the port to expect different/compatible-old versions of libraries. To get through this issue, you may suppress footprint mismatch errors and continue through. More accurately, it ignores the footprint check step.

  1. vi /etc/pkgmk.conf
  2. Uncomment and adjust the line: PKGMK_IGNORE_FOOTPRINT="yes"

Scripts issues

Connectivity issues

"Network error: Connection timed out" -- cannot SSH

SSH connection timed out

This can be caused for numerous reasons.

  1. Server is currently down
  2. attempting to connect to incorrect IP address
  3. Network routing not set up
  4. SSH server not enabled/inbound connections not allowed
  5. sshd (SSH background daemon process) not running
  6. iptables (firewall) prohibiting connection

Issued an IP address but unable to connect to internet/ping destination

If ifconfig reports an IP address issued to your interface, but you are unable to access the internet, there are a few places to check. Such behavior like this dropping 100% packets during ping.

  1. iptables -F - flushes any existing IP tables filtering rules to allow all traffic.
  2. Network routing (ethernet) not set up. Check specifically the route add default via line.
  3. Wireless routing (wifi) improperly set up. Check specifically the route add default gw line.