On Fri, Aug 08, 2008 at 11:18:20AM +0800, hhding.gnu wrote: > Hi list, > > When debian run out of memory, I can only ping the host and can't ssh to > the host. > It seems oom-killer is running but memory is still exhaust. > > What should I do then? Only reboot can solve the problem? > Can I protect oom-killer from kill the sshd then I can ssh to the box to > kill the process? I don't have a lot of experience with this, but, the couple of times I've hit this, everything runs... *REALLY* slowly. So much time is taken up by the swapping that it takes *forever* for anything to happen. Even a simple login can take several minutes. So first, be patient. Second, you *can* control how this all behaves. It appears, in my reading, that the default configuration causes malloc() to *always* succeed and then the oomkiller comes out to play eventually. You can configure this through sysctl. see here: http://opsmonkey.blogspot.com/2007/01/linux-memory-overcommit.html for info on it. There is a better article out there, but I can't find it atm. The idea is to set vm.overcommit to 2 so that malloc() will fail when you run out of memory. This causes the app trying to malloc() to get a fail on malloc() and consequently handle it (gracefully or not). But it keeps the oomkiller from coming out. another trick is to us ulimit -v <some amount of memory> to control how much memory a process has access to. man bash and look for ulimit. hope this helps and hopefully someone else with more knowledge will come along correct me... A
Attachment:
signature.asc
Description: Digital signature