Network disconnect is freezing my systems - v4.1
Forum: Networking
Topic: Network disconnect is freezing my systems - v4.1
started by: john.martzouco
Posted by john.martzouco on Dec. 23 2007,00:53
This only happens if I'm running under a WM. I'm trying JWM today, but we've seen the issue many times with Fluxbox over the past few days. I can perform the same action with a shell only and can recover because the system stays receptive.Let me describe one scenario. I'm downloading an album from <a href="www.jamendo.com" rel="nofollow" target="_blank">Jamendo</a> and my wifi loses connection with the AP. I'm using rtorrent in a console window. When this happens I can't find any way to use the WM any more. Ctrl+Alt+Bksp doesn't work - navigating to another desktop with the keyboard shortcuts doesn't work.
At this point, the Caps Lock light is flashing on my laptop and so is what seems to be the Scroll Lock light. There's no way to recover, I have to power off the machine.
I'm already trying to figure out < about the network connection drop >, but this freezing situation is much more important now.
How can I track what is going wrong in the WM environment when this happens?
The details:
1) DSL v4.1, trad hd install
2) JWM
3) rtorrent downloading < this >.
We've had the same thing happen with Firefox running under Fluxbox. This rules out the WMs, the apps. We have two laptops... it happens on both. This rules out hardware. I bet the same thing would happen if I was running hardwired to ethernet if I disconnected the cable.
Thanks.
Posted by ^thehatsrule^ on Dec. 23 2007,01:40
That problem is known as a kernel panic. If you only get this when you're on your wifi network, my guess your problem with be with those drivers. There could be a problem with the # of connections (i.e. torrent) that causes this, if this only happens when you're connected on that program.
Posted by john.martzouco on Dec. 23 2007,01:58
Thanks hats,If the information at < wikipedia > is correct, a kernel panic is what we call a Screen of Death in Windows.
My system doesn't dump memory, or reboot. This seems more like a freeze than a fatal crash.
I'm using ndiswrapper, wpa_supplicant.
Posted by curaga on Dec. 23 2007,08:30
Unless it's a serious kernel panic, magic sysrq should still work.sysrq + s = emergency sync
sysrq + u = emergency umount
sysrq + b = instant reboot
By doing this, you avoid all loss of data and don't even need to fsck after the reboot.
There's also sysrq + k (kill everything but init), but it might not work.
Oh, in Linux kernel panics don't create anything flashy (or blue ;)), they usually just hang.
Posted by john.martzouco on Dec. 23 2007,11:57
Thanks curaga,Is sysrq mapped to one, or a combination of keys in DSL v4.1? Are the mappings the same for JWM and Fluxbox?
Posted by curaga on Dec. 23 2007,13:54
It depends on your keyboard, not software. It's either it's own key, usually next to Print Screen, or combined with a key, again usually Print Screen.For example on the laptop I'm on currently it's combined with print screen, and used as alt + printscreen.
Posted by john.martzouco on Dec. 23 2007,14:49
Thanks curaga! I found it. All these years, I've been wondering what that does.OT: Anybody know what the "Scroll Lock" does?
Posted by john.martzouco on Dec. 23 2007,14:52
| Quote (curaga @ Dec. 23 2007,03:30) |
| sysrq + s = emergency sync sysrq + u = emergency umount |
What is emergency sync?
Does emergency umount unmount everything?
Posted by curaga on Dec. 23 2007,15:54
Emergency sync is just a sync that has highest priority, and emergency umount unmounts everything it can, and remounts the rest read-only..In Linux Scroll Lock is the equivalent of windoze's "Pause/Break". It pauses the current program, and pressing again lets it continue. Try catting a large file, for example
It also has some use in some spreadsheets, even MS excel..
Posted by john.martzouco on Dec. 23 2007,16:07
Thanks curaga,What's a sync? What does it do? When would I need one?
Posted by curaga on Dec. 23 2007,17:25
It flushes all data to disk, from all buffers etc. It's useful with slow devices, ie usb sticks, or when wanting to prevent data loss during a hang. Umount does it before unmounting, otherwise you would lose data all the time :PTry the command, sync
Posted by john.martzouco on Dec. 23 2007,20:21
Thanks curaga,I understand that.