On Wed, Jun 27, 2012 at 2:33 AM, Dieter BSD <[email protected]> wrote: >>> Robert writes: >>>> 3) the box is responsive to hitting enter at the console (it produces >>>> another login: prompt) >>> >>> Getty is in memory and can run. >>> >>>> 5) if I try to login to the console, it lets me enter a username then >>>> locks up totally, it does not present me with a password: prompt. >>> >>> Login(1) is not in memory, and the kernel cannot read it from disk >>> for some reason. >>> >>> I can get this symptom by writing a large file to a disk on a >>> controller that FreeBSD doesn't support NCQ on. I assume there >>> is a logjam in the buffer cache. Something trivial like reading >>> login in from disk that would normally happen in well under a >>> second can take many minutes. >>> >>> Perhaps geli is causing a similar logjam? Does it hang forever or >>> is it just obscenely slow? If it truely hangs forever it is >>> probably something else. Is there disk activity after it hangs? >>> Can you try it without geli? systat -vmstat might provide a clue. >> >> Well, it is geli. I'm unable to reproduce the freeze on the same >> exact system with everything else the same except for no geli. I'm >> going to move this thread over to geom, and continue it there. Thanks >> for your help! > > It occurs to me that it will need twice as much memory for disk i/o. > 1 buffer for encrypted and 1 for unencrypted. I know nothing about geli, > so I don't know if it uses the buffer cache for both, or what. > Could it be that the kernel isn't keeping enough memory free and > manages to paint itself into a corner and not have space to store > the unencrypted version of disk reads, and can't page/swap anything > out to make space because it doesn't have space to store the encrypted > version to write?
I think that's probably about what is happening. I'm still waiting for an answer on the geom mailing list, but I will do some testing with increasing memory sizes and see where the problem stops occurring. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
