On Tue, Jan 04, 2011 at 10:14:11AM +0800, Jeff Jansen wrote: > On Wednesday 22,December,2010 12:01 AM, Herbert Poetzl wrote: > > if you are interested in tracking this down, please pay a visit > > to the IRC channel (#vserver @ irc.oftc.net) where we can debug > > this in detail (you need a test system and a kernel build tree > > to test with :) > I definitely would be interested in working on this. Pardoning > my ignorance, what timezone are you in? :-) I'm in UTC+8. I'm in GMT+1 but as you can see from this reply, my 'working hours' do not match the timezone :) > Right now I'm working on this in Virtual Box. So I've got > Debian Squeeze as the host running in Vbox and then Lucid > as a vserver guest. I'd probably use kvm with a serial console instead, but if that works for you, it's fine for me ... > (I see exactly the same behavior in VBox as on a "real" server. > Will troubleshooting work in Virtual Box or do I need to install > all this on a physical server again? there shouldn't be any (relevant) difference between them, so no need to use a physical machine .. > >> If I go into "/etc/init/ssh.conf" and comment out the > >> "expect fork" line and then change 'exec sshd' to 'exec > >> sshd -d' (so sshd won't fork), then SSH starts and stops > >> correctly using upstart. > > I presume this simply disables the ptrace completely, > Yes, exactly. The "expect fork/daemon" config line tells Upstart > to use ptrace to "follow" the program as it forks and exits, so it > doesn't record the wrong PID. By removing that and telling the program > not to fork and "daemonize", upstart properly tracks the PID without > using ptrace. so we basically have to find out where ptrace behaves differently in a guest than on the 'host', which means that you need to have two setups, the existing one and one with the 'guest' as 'host' installation to compare best, Herbert > > note that I'm not convinced that ptracing services is a good > > idea in the first place, mainly because of performance > > implications. > The upstart developer agrees with you. He says at this point he's > convinced ptrace is NOT the way to do this and is working on a rewrite > of the functionality for the next version. But no timeframe for the > new version nor does that solve the problem for distros like lucid > which use the present version. > Thanks again. > Jeff Jansen