12.04 freezes and crashes

There are some commandline tweaks you can try, but first make certain that you have all your data safely backed up. Data loss is highly likely at this point. Are there any error messages, and can CTRL+ALT+F1 be used to bring up the full screen terminal after freeze? If so you can do a proper shutdown from there. The other thing you should try is burning a live-DVD and booting from that to see if 12.04 runs OK on your hardware. Also you might want to log in using the Unity 2D mode.

Can you please post your system specs (cpu ram etc). Have you checked that your components are not overheating (if you have a desktop). From which version did you upgrade and did you upgrade before that. Have you managed to install graphics drivers???

When does the system freeze? at random no matter what you do or immediately after power on, resume from hibernate etc???

The more specific details you can give us the greater the likelyhood we can help.

Thanks

Is your machine a laptop or a Desktop !

Have you test the RAM . with memtest !

what if you lo in to a different session ..

could you pastein the out output of the following : to paste.ubuntu.com , and post the link here please

lspci | grep VGA

and

sudo lshw -C video

and

grep -c processor /proc/cpuinfo

CTRL+ALT+F1 gets me a totally black and blank screen from which I then just turn off machine to start over.

Have Dell Inspiron D530 desktop with Intel Pentium Dual Core Processor E2180 (2.00GHZ;800FSB); 2 GB of memory and 250 GB hard drive.
System does not appear to be overheating. Problem occurs most frequently after startup, but does happen later as well.
Upgraded from 11.10 after upgrading from 11.04 after upgrading from 10.10 after upgrading from 10.04 all the way back to 8.04.
Have Nvidia graphics driver which came with machine; active driver says it is 3D capable.

Usage: lspci [<switches>]

Basic display modes:
-mm Produce machine-readable output (single -m for an obsolete format)
-t Show bus tree

Display options:
-v Be verbose (-vv for very verbose)
-k Show kernel drivers handling each device
-x Show hex-dump of the standard part of the config space
-xxx Show hex-dump of the whole config space (dangerous; root only)
-xxxx Show hex-dump of the 4096-byte extended config space (root only)
-b Bus-centric view (addresses and IRQ's as seen by the bus)
-D Always show domain numbers

Resolving of device ID's to names:
-n Show numeric ID's
-nn Show both textual and numeric ID's (names & numbers)
-q Query the PCI ID database for unknown ID's via DNS
-qq As above, but re-query locally cached entries
-Q Query the PCI ID database for all ID's via DNS

Selection of devices:
-s [[[[<domain>]:]<bus>]:][<slot>][.[<func>]] Show only devices in selected slots
-d [<vendor>]:[<device>] Show only devices with specified ID's

Other options:
-i <file> Use specified ID database instead of /usr/share/misc/pci.ids.gz
-p <file> Look up kernel modules in a given file instead of default modules.pcimap
-M Enable `bus mapping' mode (dangerous; root only)

PCI access options:
-A <method> Use the specified PCI access method (see `-A help' for a list)
-O <par>=<val> Set PCI access parameter (see `-O help' for a list)
-G Enable PCI access debugging
-H <mode> Use direct hardware access (<mode> = 1 or 2)
-F <file> Read PCI configuration dump from a given file
steve@steve-Inspiron-530:~$ sudo lshw -C video
[sudo] password for steve:
  *-display
       description: VGA compatible controller
       product: G86 [GeForce 8300 GS]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:16 memory:fa000000-faffffff memory:d0000000-dfffffff memory:f8000000-f9ffffff ioport:cf00(size=128) memory:fb000000-fb01ffff
steve@steve-Inspiron-530:~$ grep -c processor /proc/cpuinfo
2
steve@steve-Inspiron-530:~$

The 'totally black screen' is a full screen terminal with a login prompt at the top. First give your login name, then your login password. CTRL+ALT+F2 should also give you a full screen command terminal. CTRL+ALT+F7 returns you to the desktop. Have you tried logging in with the Unity 2D mode? If this works, there could be a problem with your nvida driver.

How does one log in in the 2D mode?

Using "CTRL+ALT+F!" doesn't help. Monitor goes into power saving mode and so no prompt of any kind visible. Only thing I can do at that point is turn machine power off and then restart.

You log in to 2D mode at the login screen. At the side of your password prompt is an 'Ubuntu' symbol. Click that and you get the 2D/3D option. CTRL+ALT+F1 does not put the monitor into power-saving mode. The black screen is a full screen terminal. At the very top is a prompt asking for your username. Put that in followed by enter, and then put your password in followed by wnter.

are you saying that pressing Ctrl+Alt+F1 or F2-6 does not respond and wont drop you to a text-console !

from the output of " sudo lshw -C video " looking at the configuration Line:

the Nvidia Proprietary driver " Nvidia" whitch is used by installing the Nvidia-current package is causing the issue for you .

 #See

https://help.ubuntu.com/community/BinaryDriverHowto

https://help.ubuntu.com/community/BinaryDriverHowto/Nvidia

if you could boot to the recovry mode , you might wanna try to purge the Proprietary driver

and on reboot the open source one ( Nouveau ) should be detected .

you might have to hold Shift down while booting to get the GRUB option for Recovery Console.

after Dropping to a Root Shell Prompt from the Recovery Console:

mount -n -o remount,rw /
apt-get purge nvidia-current
rm /etc/X11/xorg.conf
reboot now

if you installed from a homemade cd have you checked that the iso md5sum is the same as on the website??? if it isnt then you dont have a proper copy then it will cause all sorts of errors...

Sary,
I can get to the recovery console; how do I get to the "root shell prompt"?

Anton,
Upgraded to 12.04 from 11.10 via the update manager; did not use downloaded cd.

Downloaded 12.04 to cd, checked disc and then re-installed to pc. Also deactivated proprietary Nvidia drivers. Now seems to work ok.

Good to know .

Now I had a similar issue until i switched to the open-source driver

https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1001066