trying to disable screen "blanking"

WindowBreaker · 11-12-2008, 08:45 AM

I'm a slack user who is having to manage an Archlinux machine. I posted this question with no help on the archlinux forums, so am hoping any fellow slacker can offer some advice.

On the arch machine, which does not have X installed, the virtual consoles will go blank after 10-15 minutes. Googling revealed the culprit may be the 'setterm' command in a startup script. However, there is no 'setterm' command being issued anywhere that I can see - and I've searched the entire HD.

When I login to a virtual console and issue 'setterm -blank 0', it will in fact disable screen blanking. The problem is that nobody is usually logged in, so I can't simply add the 'setterm' command to a bash startup script.

/etc/inittab shows the following for virtual consoles.

Code:

c1:2345:respawn:/sbin/agetty -8 38400 vc/2 linux

Is this a problem/default with 'agetty'? Any help would be appreciated.

bgeddy · 11-12-2008, 09:13 AM

On a Slackware system /etc/rc.M has this :

Code:

# Screen blanks after 15 minutes idle time, and powers down in one hour
# if the kernel supports APM or ACPI power management:
/bin/setterm -blank 15 -powersave powerdown -powerdown 60

Don't know if Arch does too. Are you sure you've checked the entire disk ?

masonm · 11-12-2008, 09:34 AM

Well I don't understand why it's a problem if no-one is logged in, but if you really want to fix it put the setterm command into rc.local which is the last thing run during startup. Doesn't matter if anyone is logged in or not, it'll still run during startup.

WindowBreaker · 11-12-2008, 10:17 AM

Quote:

Originally Posted by masonm

Well I don't understand why it's a problem if no-one is logged in

This is running on a hardware router, which randomly locks-up every 4-6 weeks. At that point, the keyboard is unresponsive, it is not accessible from the network, and the monitor reveals nothing because it has been blanked. My only recourse is to pull the power cord and restart it.

I've painfully searched every logfile and see no indication of a problem. I suspect a hardware issue and would like the see any errors output to the console prior to the crash. In order to do that, I must prevent the machine from "blanking" the console.

I will add the 'setterm' command to rc.local and reboot the box. My only concern is whether it will affect all virtual consoles. I will test it and post the results here for others.

Thanks for the tip.

masonm · 11-12-2008, 06:00 PM

Quote:

Originally Posted by WindowBreaker

This is running on a hardware router, which randomly locks-up every 4-6 weeks. At that point, the keyboard is unresponsive, it is not accessible from the network, and the monitor reveals nothing because it has been blanked. My only recourse is to pull the power cord and restart it.

I've painfully searched every logfile and see no indication of a problem. I suspect a hardware issue and would like the see any errors output to the console prior to the crash. In order to do that, I must prevent the machine from "blanking" the console.

I will add the 'setterm' command to rc.local and reboot the box. My only concern is whether it will affect all virtual consoles. I will test it and post the results here for others.

Thanks for the tip.

Ah ok, that makes sense. The setterm command, placed in rc.local, will prevent blanking on all consoles. Read the man page for setterm.

WindowBreaker · 11-12-2008, 07:47 PM

per masonm's suggestion, I added

Code:

setterm -blank 0

to rc.local and have verified that it does in fact work on all virtual consoles even though nobody is logged in.

Also, I modified syslog-ng to write all console messages to /var/log/console.log in addition to the console. So I guess I solved my problem 2 different ways.

Posting here in case it helps anyone.