Unbootable system: fdisk does not see partitions, but parted does

[Sander van Noort]

Hi,

I have a problem with my partition table, which makes the system
unbootable. Parted sees my partitions, but the kernel does not. If
this not the right list to post my problem, please tell me where I
could find help.

I have a Powerbook G4 dualboot with OSX and Ubuntu. OSX starts fine
but if I select Ubuntu, yaboot starts it, but then it hangs at the
Ubuntu splash screen (probably because the root partition is not
found). I have done the following tests by booting from the ppcrcd
live cd.

During boot, no partitions are recognised
# dmesg | grep hda
[   92.238964] hda: ST9100823A, ATA DISK drive
[   92.910783] hda: Enabling Ultra DMA 5
[   94.667101] hda: max request size: 1024KiB
[   94.923239] hda: 195371568 sectors (100030 MB) w/8192KiB Cache,
CHS=16383/255/63, UDMA(100)
[   94.923761] hda: cache flushes supported
[   94.932608]  hda:

# ls /dev/hda*
/dev/hda

fdisk sees nothing, sfdisk sees (4 times?) nothing, but parted sees
the partitions
# fdisk -l /dev/hda

Disk /dev/hda: 100.0 GB, 100030242816 bytes
255 heads, 63 sectors/track, 12161 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

  Device Boot      Start         End      Blocks   Id  System
# sfdisk -l /dev/hda

Disk /dev/hda: 12161 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

  Device Boot Start     End   #cyls    #blocks   Id  System
/dev/hda1          0       -       0          0    0  Empty
/dev/hda2          0       -       0          0    0  Empty
/dev/hda3          0       -       0          0    0  Empty
/dev/hda4          0       -       0          0    0  Empty
# parted /dev/hda print

Disk /dev/hda: 100GB
Sector size (logical/physical): 512B/512B
Partition Table: mac

Number  Start   End     Size    File system  Name     Flags
1      0.51kB  32.8kB  32.3kB               primary
 6      32.8kB  2033kB  2000kB  hfs          primary  boot
 3      134MB   15.0GB  14.9GB  hfs+         primary
5      27.1GB  32.4GB  5243MB  ext3         primary
2      32.4GB  42.9GB  10.5GB  ext3         primary
7      42.9GB  98.0GB  55.2GB  fat32        primary
 4      98.0GB  100GB   2000MB  linux-swap   primary  swap

Now I let partprobe reread the partition table
Note that I have not done changed anything on the partition table since booting
# partprobe /dev/hda

Now the partitions show up. They can be mounted and there seems to be
nothing wrong with them.
fdisk and sfdisk however still don't see the partitions
# ls /dev/hda*
/dev/hda
/dev/hda1
/dev/hda2
/dev/hda3
/dev/hda4
/dev/hda5
/dev/hda6
/dev/hda7

If I reread the kernel partition table with sfdisk
# sfdisk -R /dev/hda

All the partitions are gone again
# ls /dev/hda*
/dev/hda


What is going on, what is the difference between "partprobe" and
"sfdisk -R". And how can I make my Ubuntu bootable again? The problems
started after I resized a partition with parted.


Thanks,
Sander