Search:  
Gentoo Wiki

HOWTO_Troubleshoot_Gentoo_Install

Contents

Problems with ALSA

Sound is muted every reboot

Part 1: Configure ALSA for save and restore

Make sure you set alsa configuration to be saved on shutdown and restore on start with either of:

rc-update add alsasound boot
rc-update add alsasound default

Generally, unless you must put it in boot, default is fine.

Part 2: Shutdown cleanly when you shutdown

When possible, to shutoff your computer use a command not the off switch:

Problems booting

Understand the boot process to make sure you made no mistakes.

The boot process:

Step 1: System reads master boot record off of disk

You must have written an MBR to the disk.

Beware of conflicts with your MBR

You must make sure nothing conflicts with the MBR: you must use a partition map.

Writing a master boot block

GRUB is preferred over lilo, as GRUB does not need an update program to be run when a change is made to configuration information.

You can either use grub-install or the grub shell to write your MBR. We suggest you use the grub shell as it a more raw interface which gives you more control and it is very easy to use.

Grub uses the BIOS to work with your drive and enumerates your drives and partitions starting with zero. So your first drive is (hd0). The first partition on your first drive is (hd0,0). More precisely, the first drive according to your BIOS. It is unlikely, but possible for your BIOS to play games with you and have a different enumeration at boot time. In this case, you will want to use the --device-map option when running the grub shell.

For Grub to be your first boot loader (there are alternatives), you want to have Grub write the MBR to the device, not the partition. So you will use something like (hd0), not (hd0,0).

mount /boot
cd /boot
grub
root (hd0,0)
setup (hd0)
quit

Step 2: Grub reads its configuration info

Note: More to come

Step 3: Grub tries to load the kernel

In your grub config, the root line tells Grub on which partition your compiled kernel is.

Note: More to come

Problems with CDs

Issues reading or mounting the CD

CD doesn't support needed hardware

Problems with clock

Unless you dual boot with windows, your clock should be set in UTC.

Part 1: Fix your clock setting

With network access

Get the time from NIST:

rdate -s time.nist.gov

After setting the clock, store the time so the time will be correct on boot:

hwclock -w

Without network access

On a machine with the correct time:

echo date -u `date -u +%m%d%H%M%Y`

This will give you a command to use to set the clock. (e.g. date -u 012103542008)

After setting the clock, store the time so the time will be correct on boot:

hwclock -w

Part 2: Fix your clock configuration

Edit /etc/conf.d/clock:

Make sure the clock will be recovered and stored on startup and shutdown:

rc-update add clock boot

Part 3: Fix your clock display

To fix the time shown by commands such as date and ls:

/etc/init.d/clock pause start

Part 4: Configure your clock to be regularly updated

See: NTP

Part 5: Shutdown cleanly when you shutdown

When possible, to shutoff your computer use a command not the off switch:

Part 6: Fixing times in the future

This will show you which files have modification times within the current minute and in the future:

find / -xdev -mmin '-0' -exec echo '{}' \;

To actually set the modification time to the current time, in the above command change echo to touch.

Problems with nVidia

Make sure you have selected nVidia's OpenGL implementation

To see your available and current OpenGL implementations:

eselect opengl list

Sample output:

Available OpenGL implementations:
  [1]   nvidia *
  [2]   xorg-x11

The asterisk indicates the current selection.

To set the current implementation:

eselect opengl set N

Where N is a number of the implementation you want.

Problems with Grub

Grub says file not found on boot

Fixing a reiserfs /boot which was mounted without notail

Part 1: Fix fstab for future boots

Edit /etc/fstab, add notail to the options for /boot.

Example:

/dev/md1  /boot    reiserfs   noauto,noatime,user_xattr,notail  1 1

Part 2: Remount /boot correctly

To remount /boot with notail:

mount -o remount,notail /boot

Part 3: Rewrite the files in /boot

mkdir /boot.bad
mv /boot/* /boot.bad/
cp -pvr /boot.bad/* /boot/

After successfully booting, you may remove /boot.bad.

Problems with nvidia-drivers

emerge reports Could not detect kernel version

You must have a symbol link in /usr/src called linux pointing to your current kernel.

To see your current settings:

cd /usr/src ; ls -l

Sample output:

lrwxrwxrwx  1 root   root     14 Dec 26 17:11 linux -> linux-2.6.18.5
drwxr-xr-x 19 root   root    712 Oct 13  2006 linux-2.6.18.5

To add the missing link:

cd /usr/src ; ln -s linux-YOUR_VERSION linux

Problems with software RAID

Elements are not automatically added to the RAID at boot

Make sure your partition types for automounting are: fd

To view all partitions:

fdisk -l

Sample output:

 Disk /dev/sda: 74.3 GB, 74355769344 bytes
255 heads, 63 sectors/track, 9039 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1           8       64228+  fd  Linux raid autodetect
/dev/sda2               9        9039    72541507+  fd  Linux raid autodetect

Disk /dev/sdb: 74.3 GB, 74355769344 bytes
255 heads, 63 sectors/track, 9039 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1           8       64228+  fd  Linux raid autodetect
/dev/sdb2               9        9039    72541507+  fd  Linux raid autodetect

RAID rebuilds every start up

mdadm /dev/mdX -Gb internal

Problems with swap

Unless you are going to share a swap with another OS, there is little benefit to using a swap partition. Use a swap file. A swap file allows you to resize it at your convenience.

Retrieved from "http://www.gentoo-wiki.info/HOWTO_Troubleshoot_Gentoo_Install"

Last modified: Tue, 22 Jan 2008 11:14:00 +0000 Hits: 2,085