I compiled the latest trunk for x86 and I get the following message during the boot process:

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

I checked that scsi support it enabled in the kernel. What else should I select in the kernel config to have it work?

Thank you.

tanguy

Here is the exact message at boot. It used to work 2 weeks ago.

AMD Geode RNG detected                                                         
Serial: 8250/16550 driver, 2 ports, IRQ sharing disabled                       
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a NS16550A                         
serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a NS16550A                         
scsi0 : pata_amd                                                               
scsi1 : pata_amd                                                               
ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0xff00 irq 14                 
ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xff08 irq 15                 
PNP: No PS/2 controller found. Probing ports directly.                         
i8042.c: No controller found.                                                   
mice: PS/2 mouse device common for all mice                                     
TCP westwood registered                                                         
NET: Registered protocol family 17                                             
802.1Q VLAN Support v1.8 Ben Greear <greearb@candelatech.com>                   
All bugs added by David S. Miller <davem@redhat.com>                           
Using IPI Shortcut mode                                                         
VFS: Cannot open root device "sda2" or unknown-block(0,0)                       
Please append a correct "root=" boot option; here are the available partitions:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) 
Pid: 1, comm: swapper Not tainted 2.6.31.5 #1                                   
Call Trace:                                                                     
[<c101f6c7>] ? panic+0x47/0xf0                                                 
[<c12b7b10>] ? mount_block_root+0x1d0/0x270                                   
[<c1002930>] ? do_notify_resume+0x3f0/0x910                                   
[<c12b7bf7>] ? mount_root+0x47/0x60                                           
[<c12b7d15>] ? prepare_namespace+0x105/0x140                                   
Clocksource tsc unstable (delta = 89985171 ns)                                 
[<c12b7222>] ? do_initcalls+0x12/0x20                                         
[<c12b75cf>] ? kernel_init+0x10f/0x120                                         
[<c12b74c0>] ? kernel_init+0x0/0x120                                           
[<c1003813>] ? kernel_thread_helper+0x7/0x14

What root device is given in the command line? It should be /dev/sda2. If you used an older checkout and did not update the config it is still /dev/hda2 maybe which leads to the error you see.

~ JoW

The root device is not the problem. I also tried /dev/hda2 or /dev/sda2, it's always the same. If I change the kernel with the snapshot's one, it works. There must be something missing in the kernel'config. I could get it working after enabling the IDE in the kernel'config and using /dev/hda2 in this case. I suspect there have been a change recently in the config about the scsi stuff.