Date: Wed, 27 Jun 2012 02:33:59 -0400 From: "Dieter BSD" <dieterbsd@engineer.com> To: freebsd-hackers@freebsd.org Subject: Re: Freeze when running freebsd-update Message-ID: <20120627063400.298430@gmx.com>
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>> 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?
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