Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a DELL Inspiron 7520 in the highest configuration:

3rd Generation Intel® Core™ i7-3612QM processor (6M Cache, up to 3.1 GHz)
15.6" Full High Definition (1080p) LED Display
8GB3 Dual Channel DDR3 SDRAM at 1600MHz
1TB 5400RPM SATA HDD + 32GB mSATA SSD w/Intel Smart Response
Blu-ray Disc (BD) Combo (Reads BD and Writes to DVD/CD)
AMD Radeon™ HD 7730M 2GB
6.09 lbs

and I have installed Ubuntu 12.04 few days ago and I'm facing some issues:

1) Sometimes the whole ntb freezes and I have to hold power button for 5 secs to shut it down. I think it is something with VGA and connected external monitor. I have read somewhere that it is already a reported bug, but what I am not sure about that it is doing sporadically. Sometimes it freezes right after I log in, sometime I ran few hours and then it freezes. I am using those proprietary drivers but I wasn't been able to install those with updates.

2) The next issue is the fan is quite noisy even when the ntb is almost Idle. (max 10% CPU usage). Can you recommend me some software which could do this power management to minimize the noise? I have tried CPU frequency scaling indicator, but it seems that it has not any effects.

3) When I want to log out, restart or shutdown using the menu in upper right corner the upper and left trays disappear, but programs are still running and they won't close to complete log out or shutting down the OS. When I use the CLI command, it works fine.

Thanks for any help you can provide.

share|improve this question

The solution to #2 seems to be:

$ echo "min_power" | sudo tee /sys/class/scsi_host/host*/link_power_management_policy

But it gets reset at startup or at resume from suspend/hibernate...

So make a script (e.g. /home/user/.powerfix) with the following content:

sleep 5 && echo "min_power" | tee /sys/class/scsi_host/host*/link_power_management_policy

Mark it as executable and then put sh /home/user/.powerfix into /etc/rc.local, before the exit 0 command so it runs at startup. Next, to run it at resume make a file named /etc/pm/sleep.d/90_minpower with the following content:


case "$1" in
        sh /home/user/.powerfix &
share|improve this answer
will it remain like that even after rebooting the computer or we will have to write those command each time we boot up? is there way to make it permanent? – Jeff Labonte Dec 7 '12 at 4:42
I've updated the answer. – HairyFotr Dec 9 '12 at 14:26
but the thing is that I doesn't start when I reboot the computer, if I do it manually it says; tee: /sys/class/scsi_host/host0/link_power_management_policy: Permission denied tee: /sys/class/scsi_host/host1/link_power_management_policy: Permission denied tee: /sys/class/scsi_host/host2/link_power_management_policy: Permission denied tee: /sys/class/scsi_host/host3/link_power_management_policy: Permission denied tee: /sys/class/scsi_host/host4/link_power_management_policy: Permission denied tee: /sys/class/scsi_host/host5/link_power_management_policy: Permission denied – Jeff Labonte Dec 11 '12 at 4:01
rc.local and sleep.d/ scripts run with root privileges, so they don't need sudo. But you need sudo if you run from the console. It's there in the first example, or if you want to run the script as root, you can run sudo sh .powerfix. – HairyFotr Dec 11 '12 at 15:11

I've gotten a problem like #1 in yours before

After trying many things the solution was BIOS update

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.