[DRBD-user] RHEL 5 - DRBD problems

[rotseN]

I am getting this errors when running the command "drbdadm adjust mysql" 
on WAHOO:
Failure: (114) Lower device is already claimed. This usually means it is
mounted.
Command 'drbdsetup /dev/drbd0 disk /dev/sda2 /dev/sda2 internal 
--set-defaults --create-device --on-io-error=detach' terminated 
with exit code 10

And on my second node WAHOO2, I get:
No response from the DRBD driver! Is the module loaded?
Command 'drbdsetup /dev/drbd0 disk /dev/sda2 /dev/sda2 internal 
--set-defaults --create-device --on-io-error=detach' 
terminated with exit code 20


This is what my /etc/drbd.conf file looks like:
resource mysql
{
  protocol C;

# incon-degr-cmd "echo '!DRBD! pri on incon-degr' | wall ; sleep 60 ; halt -f";

  startup { wfc-timeout 0; degr-wfc-timeout 120; }
  disk { on-io-error detach; } # or panic, ...
  syncer {
#    rate 6M;
  }

  on wahoo {
    device /dev/drbd0;
    disk /dev/sda2;
    address 10.100.1.170:7789;
    meta-disk internal;
  }

  on wahoo2 {
    device /dev/drbd0;
    disk /dev/sda2;
    address 10.100.1.171:7789;
    meta-disk internal;
  }
}
-------------------------

Any ideas?

thanks,

rotseN