# every shell hangs



## bany (Sep 14, 2009)

Hi,

I dont know if this is the correct place to ask, and I dont even know if it is a FreeBSD issue (I think so) or a XFCE one.. Ill post in both forums..

Im runing FreeBSD 7.2 with xfce 4.6.0

yesterday something strange happended and I dontknow what it was, how to prevent it from happening againg or what to do in case..

I was downloading some stuff with rTorrent in a terminal.. and in another terminal I was burning a cd with burncd..

now, after burncd reached 100% it said "fixating cd, please wait.."

after 5 minutes it was still stuck like this.. I did a ^c and nothing.. nor ^d..

I clicked on the other terminal, quit rTorrent and I had my prompt..
now I went with a ps..
and nothing.. after hitting <enter> the shell hunged.. I could still type.. but no answer from the shell..

then I noticed I could click with the mouse in both terminals and flip flop between the two,  but the rest of the desktop was frozen.. no click on the desktop, panels, menu and so on..

I went on a text console, and had my text-based login: prompt
typed root, hit <enter> ..and then again nothing.. no Password: prompt, nothing..

I tried to push the power button to force a reboot but I had on messages:

kernel: acpi: suspend request ignored (not ready yet)
kernel: acpi: request to enter state S5 failed (err 6)

I had to shut down manually..

When I checked /var/log/messages I found nothing.. no messages.. nothing..

any ideas? is there a tool or a log file I can check to find out what happened?

thnx

PS: while I was still in xfce, I noticed a window on the taskbar titled "cursor-<something>" which shouldnt have been there.. but it was iconified and since it was all frozen (except for the two terminals) I couldnt maximize it.. so I dont know what it was..


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## roddierod (Sep 14, 2009)

Although many people like burncd, I have never been able to use it because the fixate part never works. There was a work around years back that said to burn you cd without the fixate option and when that command finish run burncd again with only the fixate option. That also failed for me.

I've never used rTorrent but, Transmission and pyBittorrent would cause X to lock on me if I was downloading and seeding too many torrents. I always suspected memory leaks in the two apps, but I used deluge and have not had that issue.

Don't know if this was helpful...probably rambly...


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## fonz (Sep 14, 2009)

bany said:
			
		

> now, after burncd reached 100% it said "fixating cd, please wait.."
> 
> after 5 minutes it was still stuck like this.. I did a ^c and nothing.. nor ^d..
> 
> ...


My educated guess is that burncd may have caused some kind of I/O deadlock when trying to fixate the disc. As roddierod mentioned, the fixating stuff is a bit dodgy.

The "workaround" of first running burncd without the fixate command and then run burncd fixate separately does work for me (I've been doing it for years as a precautionary measure), so I suggest that you try that first.

Alphons


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## bany (Sep 15, 2009)

fonz said:
			
		

> My educated guess is that burncd may have caused some kind of I/O deadlock when trying to fixate the disc. As roddierod mentioned, the fixating stuff is a bit dodgy.



Yes I was thinking something like this but what puzzlezs me is that a single application blocks the whole OS.. I didnt think this was possible.. what I think was really weird is that even switching to another console and try to login didnt work..

could I have tried something instead of powering off?


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## fonz (Sep 16, 2009)

bany said:
			
		

> but what puzzlezs me is that a single application blocks the whole OS.. I didnt think this was [/possible..


It _shouldn't_ happen, no, but particularly X is known to occasionally cause hangups when something weird happens. It looks to me like X.org is already a lot less prone to this than the old X11R6 so things have improved, but still.



			
				bany said:
			
		

> what I think was really weird is that even switching to another console and try to login didnt work..


I think that's probably because getty(8) (the program that waits for you to log in (among other things)) is I/O-bound. Its interrupt, telling it that some input (your username) is ready, probably got lost when burncd(8) deadlocked the I/O system.



			
				bany said:
			
		

> could I have tried something instead of powering off?



I can think of two things that may or may not have worked:
Giving X the 3-finger salute (Ctrl-Alt-Backspace). It certainly costs you your X session, but *if* it works it should cause burncd(8) to be terminated, hopefully breaking the deadlock.
Remote login. If you can login remotely (probably not, because of the same getty(8) problem, but it's worth a shot) you can arm kill(1) and start shooting, hopefully restoring the system to a sane state.

Alphons


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## bany (Sep 16, 2009)

well a clear explanation at last 

I think I tried ctrl-alt-backspace.. but im not sure..

btw thank you


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