My guess is it's related to some FAKERaid integrated in the motherboard.
Disable it from BIOS if such device exists and try again. (or maybe try a BIOS upgrade)
More details from the error would be useful (the ubuntu case).
This is what I meant by FAKERaid:
Operating system-based RAID doesn't always protect the boot process and is generally impractical on desktop versions of Windows (as described above). Hardware RAID controllers are expensive and proprietary. To fill this gap, cheap "RAID controllers" were introduced that do not contain a RAID controller chip, but simply a standard disk controller chip with special firmware and drivers. During early stage bootup the RAID is implemented by the firmware; when a protected-mode operating system kernel such as Linux or a modern version of Microsoft Windows is loaded the drivers take over.
These controllers are described by their manufacturers as RAID controllers, and it is rarely made clear to purchasers that the burden of RAID processing is borne by the host computer's central processing unit, not the RAID controller itself, thus introducing the aforementioned CPU overhead from which hardware controllers don't suffer. Firmware controllers often can only use certain types of hard drives in their RAID arrays (e.g. SATA for Intel Matrix RAID, as there is neither SCSI nor PATA support in modern Intel ICH southbridges; however, motherboard makers implement RAID controllers outside of the southbridge on some motherboards). Before their introduction, a "RAID controller" implied that the controller did the processing, and the new type has become known by some as "fake RAID" even though the RAID itself is implemented correctly. Adaptec calls them "HostRAID".
A BIOS upgrade is just simple procedure recommended by your hardware manufacturer if you are not already using the latest version.
I don't think the error you showed me can be the reason why Ubuntu fails to boot.
I am still able to install the old versions of Linux. – Rohit Banga – 2010-03-23T14:06:59.170
running vista right now – Rohit Banga – 2010-03-23T14:07:23.507
FAKERaid I didn't understand. BIOS upgrade do you really think it would help. need more advice before trying this option. – Rohit Banga – 2010-03-23T14:08:20.587
Ubuntu- I chose the option try ubuntu without affecting my computer.
then after some gui loading I suddenly got initramfs command prompt. When i ran dmesg from this prompt, some 20 lines from the end i saw the message
radeon kernel modesetting DISABLED. Not sure if this has something to do with the crash.I also have Netgear WG311 wireless adapter but that worked with old version of ubuntu – Rohit Banga – 2010-03-23T14:11:19.553
can i run some command from initramfs command prompt to learn more about the cause of the error. – Rohit Banga – 2010-03-23T15:35:54.597
try this :http://ubuntuforums.org/showthread.php?t=765195&page=7
– None – 2010-03-23T15:47:52.197or this : http://ubuntuforums.org/showthread.php?t=1307780
– None – 2010-03-23T15:51:23.317there is actually an ubuntu bug similar to your problem https://bugs.launchpad.net/ubuntu/+source/casper/+bug/267180
– None – 2010-03-23T15:52:27.153I get a message saying Unable to find medium containing live file system. From the initramfs I am able to mount /dev/sda1 and /dev/sda2 and view their contents. both are ntfs.
i cannot see /dev/cdrom or /dev/sr0. I do see /dev/sg0 which happens to be a character device i was not able to mount. Is cdrom a character device. perhaps the problem is with the cd drive. the light of the drive stops blinking after this error. – Rohit Banga – 2010-03-23T19:21:09.450
The cdrom is not necessarily /dev/cdrom it can be for example /dev/hdc if you have one hard disk and one cdrom and the cdrom is secondary master :)<br> And no a cdrom is not a character device.<br> http://www.linuxhq.com/guides/LKMPG/node14.html -for more info on character devices.<br> I don't think the cdrom is the issue here.<br> I am not rude but there are so many good results on google I don't to paste the links so I will just paste the google link: http://www.google.ro/search?&q=Unable+to+find+medium+containing+live+file+system
– None – 2010-03-23T19:34:59.267then why does the cdrom light stop blinking. I can find my hard disks in /dev/sda1 and /dev/sda2 and was able to mount them. – Rohit Banga – 2010-03-24T10:21:49.560