When I reboot, the "/dev/sdx" of hard drives is changing.
For example, if I run KDE partition manager, I got this:

disk 1 --> /dev/sda
disk 2 --> /dev/sdb
disk 3 --> /dev/sdc
disk 4 --> /dev/sdd
If I reboot and rerun KDE partition manager, it becomes

disk 1 --> /dev/sda
disk 2 --> /dev/sdb
disk 3 --> /dev/sdc
disk 4 --> /dev/sdh
Ubuntu works fine except the plasmoid "Hard disk status" which don't find all hard drives.

Can I force the system to use a specific "/dev/sdx"?
Note that I use UUIDs in my FSTAB.
I presume it work better with "/dev/sdx" (I've not try) but It seems that UUID becomes the standard.

Otherswise, KDE partition manager tell me a warning:
Partition 4 does not start on physical sector boundary
on /, home & swap...

Has someone an idea?