I did both ways: creating raid right in the debian installer partman and also the other with adding second drive to a degraded raid after installation. (using debian squeeze)

So my setup is like

(I have md0 as a raid 5, doesnt matter for now) 

 /dev/md1 for /boot as ext2

/dev/md2  > crypt > vg_debian > lv_root, lv_home, lv_var > filesystems (ext4/xfs)

 In both ways I am the  getting the frequent kernel message:

bio too big device /dev/md2 (248 > 240)

 I have no clue what that might mean. Google doesnt show up so much results. But after reading trought some lists I am quite feared of facing data corruption.

I am using an compact flash card 8g on IDE port and an usb drive 8gb. Anyways they differ in size so I set up system with the USB drive (smaller) and later copied the partition table to the sd card. Maybe the problem is resulting from there.

Somebody might has an idea? What can I do? Is this kind of setup practical even setup, like everything nested (raid,crypt,lvm)?

best regards! Ben