I've just upgraded a server from Linux 2.2.16 to 2.4.20 ... and it's running quite well, except the RAID part.

I have 2 disks which are striped (RAID0) which were assigned to /dev/md0. After the upgrade i receive this message when running mdadd -ar

Warning : no checksum field for /dev/md0
/dev/hda3: No such device
/dev/hdb1: No such device
/dev/md0: No such device

I discovered I was using the old raidtools-0.41. I upgraded to the latest 1.00.3. Made a new /etc/raidtab which is comparable to the old /etc/mdtab. And then I tried to use the upgrade parameter to mkraid ...

# mkraid --upgrade /dev/md0
Handling MD device /dev/md0
analyzing super-block
cannot upgrade magic-less superblock on /dev/hda3
mkraid: aborted

The syslog says:

kernel: md: invalid raid superblock magic on hda3

Is it possible to upgrade the old md disk to be supported in the 2.4 kernel? How? Or am I doing something wrong here?

I do need to keep the old data ... any ideas are welcome!