hard drive partition problem

[splittik]

I have knoppix 3.8 installed on my hard drive and want to have two partitions. i have a main partition that has knoppix on it and works fine. When i create another partition, using cfdisk or qtpartition though and try to open it it gives me an error "Could not mount device. /dev/hda4 is not a valid block device." I have tried different partitions, ext2, ext3, and FAT32 but none of them seem to work. What's the problem here? If i resize my main partition will that erase or corrupt the data?

[Dave_Bechtel]

--Post the results of ' fdisk -l ' as root. If you repartitioned your drive but there was an active (mounted) partition or swap space, the kernel might have given you a warning about using the old partition table until the next reboot.

I have knoppix 3.8 installed on my hard drive and want to have two partitions. i have a main partition that has knoppix on it and works fine. When i create another partition, using cfdisk or qtpartition though and try to open it it gives me an error "Could not mount device. /dev/hda4 is not a valid block device." I have tried different partitions, ext2, ext3, and FAT32 but none of them seem to work. What's the problem here? If i resize my main partition will that erase or corrupt the data?

[jdebay]

I had the same problem when using the icon's on the desktop to access partitions. I thought it was qtparted? then parted? then mkfs ext2? Other linux reported problem with umounting...

but it turned out that I need DMA on boot line was default on prior versions.