Dell Updates on Linux – Another instance of SUU is already running
If you’re trying to run Dell’s SUU on a Linux box and get the error “Another instance of SUU is already running”, check out this FAQ
I have summarised the steps below:
chattr -i /var/log/dell/suu/suu.lck
rm -f /var/log/dell/suu/suu.lck
You can then run SUU 
Mahesh said,
16 November, 2011 at 10:15 am
Thank you , it worked as is..
Jason said,
1 December, 2011 at 8:30 pm
sweet dude…