[Solved]Kernel panic when bootup

Logioniz · n00b Joined: 28 Oct 2011 Posts: 11

when i bootup i have on the screen:

NeddySeagoon · Posted: Mon Oct 31, 2011 6:37 pm Post subject:

Logioniz,

unknown-block(8,6) means /dev/sda6. That you get those numbers and not (0,x) or (2,x) means your kernel can read your hard drive but it does not understand what it reads there.

This means that your root filesystem is not compiled into the kernel.

Logioniz · n00b Joined: 28 Oct 2011 Posts: 11

Thanks, NeddySeagoon

I have ext4 on root directory. i try to add rootfstype=ext4 on the grub and error changed. I don't remember what there are, probably tsomething like his: "You should to enter true root in the grub" and error panic.

lspci:

NeddySeagoon · Posted: Mon Oct 31, 2011 8:24 pm Post subject:

Logioniz,

There was no need to format and start again. You should just mount your partitions,mount /proc and /dev then do the chroot steps.
This gets you back into the chroot as if you never left it. Now you can fix you gentoo.

I have similar hardware to you. All disk devices use the SCSI software today. You must not use

Logioniz · n00b Joined: 28 Oct 2011 Posts: 11

Thanks, NeddySeagoon, but i think, that i would install 64 bit version of Gentoo.

I spent about 30 minutes in the internet, looking for some differences between ATA/ATAPI and PATA, but have been yet doubt...

So, if i want to install x64 bit system, i don't mark this option:

NeddySeagoon · Posted: Mon Oct 31, 2011 10:01 pm Post subject:

Logioniz,

To install a 64 bit Gentoo your need the amd64 liveCD and the amd64 stage3.
On such a system, the kernel option Support for large (2TB+) block devices and files will be hidden.

In the days before PCs, there were minicomputers. They mostly used the Small Computer Systems Interface (SCSI) for attaching hard drives and other things.
The various SCSI standards define both an electrical bus and a set of commands to be used over the bus. The original SCSI bus could have 8 devices attached.
SCSI was too expensive for PCs, so Shugart invented a lower cost interface (called ST502 from memory). It needed a controller card in a slot and had two cables to the drive. A data cable and a control cable. The power cable wasn't counted. In an effort to reduce costs further, Compaq and a drive manufacturer (I forget who) introduced the Integrated Drive Electronics (IDE) drive. This no longer needed an interface card, instead, it used a cut down 16bit AT interface exposed in a new 40 pin connector.
This was later dubed PATA. To make life easy, a cut down version of the SCSI command set was adopted for these drives.
CDROMs did not yet exist. After playing with some odd interfaces on sound cards, some of which where just cut down IDE interfaces, the standard IDE electrical interface was adopted by CDROMs too. However they needed some new commands. These are knows as the AT Packet Interface.

Thus IDE/PATA/ATAPI all names associated with the 40 pin connector on your motherboard that you attach older hard drives and optical drives to.
It provides a 16 bit data path between the motherboard and attached devices and its really a cut down 16 bit AT slot. Further, it uses a subset of the SCSI command set to communicate over between devices and the motherboard.

Speed wise, it reached the end of the road some time ago. The new Serial ATA interface can transfer data at higher rates.

When SATA was introduced, yet more SCSI commands were added back in. It did not make sense to write a whole new ser of drives in the kernel, so the IDE/PATA/ATAPI drivers were unitfied with the SATA drivers, under SCSI, which is really where they started out.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Logioniz · n00b Joined: 28 Oct 2011 Posts: 11

Now, i try to install x86_64 gentoo...
So, i have had this problem:

List of all partitions:
0800 sda driver : sd
...
...
0b00 sr0 driver : sr

Kernel panic - not syncing : VFS: Unable to mount root fs on unknown-block(2,0)

So, now unknown-block is (2,0).

Logioniz · n00b Joined: 28 Oct 2011 Posts: 11

not surprising, that nobody answer to me... i don't display all config files (fstab have bug)
i format drive, and uuid changed... so i delete string root=UUID=.... and write /dev/sda6...
So, thanks for help and attention...
Special thanks to NeddySeagoon.

ronstudio · n00b Joined: 14 Aug 2011 Posts: 28

Hi Logioniz,

I have encountered similar case before, https://forums.gentoo.org/viewtopic-t-890598-highlight-ronstudio.html
other than the commonly mentioned reasons like AHCI driver not enabled or filesystem EXT3/EXT4 not enabled correctly,
today I finally understand the problem I have.

The main point is it's not only select the drivers which you have, but also NOT to select the drivers which you don't use to avoid the Kernel picking up the wrong driver.

In my case, under "Serial ATA and Parallel ATA drivers",
I enabled
ATA ACPI Support
AHCI STAT support
ATA SFF support (then having sub menu)
ATA BMDMA support
Intel ESB, ICH, PIIX3, PIIX4 PATA/SATA support

This still looks normal and maybe the same as your case, but then in the bottom of the page, there is a section called,
*** Generic fallback / legacy drivers ***
I also choose
ACPI firmware driver for PATA
Generic ATA support

After I removed the last 2 drivers, my kernel successfully boot recognize my harddisk without the VFS Kernel panic problem.

Wish this could be useful to you as well.. the lesson that I learn is, it's also very important for some drivers not to select.