Date: Fri, 1 Oct 2004 20:16:51 -0400 From: Jim Durham <durham@jcdurham.com> To: freebsd-hackers@freebsd.org Subject: Re: Sudden Reboots Message-ID: <200410012016.51415.durham@jcdurham.com> In-Reply-To: <200410011636.i91GaYgC093428@ambrisko.com> References: <200410011636.i91GaYgC093428@ambrisko.com>
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On Friday 01 October 2004 12:36 pm, Doug Ambrisko wrote: > Jim Durham writes: > | I have had this problem now with at least 3 FreeBSD servers over a period > | of about 2 years. I had put it down to some hardware problem but it seems > | to be too much of a coincidence with 3 different machines doing the same > | thing. > | > | The first time was when I put 4.5-RELEASE on a brand new Dell Poweredge > | 2650. I ran it on the bench for a week or so, then decided all was well > | and put it in the server rack and started doing the company's email > | service on it. After a few weeks, it suddenly would 'reboot' for no > | apparent reason. No log entries, nothing at all except the usual stuff in > | /var/log/messages about '/ was not unmounted correctly', etc. Just like > | you had pulled the power plug. > > How much memory are in these system?. The Dell is a Dual Xeon 2650 with 2gb or Ram. The ISP's box has only 256 megs or ram and the business customer's box has 512. > If you have 3G or more you end > up with very little left for the kernel in the 2G space Can you elaborate on why this is? > . You can > monitor how much space you have left by compile a debug kernel then > as root: > gdb -k kernel.debug /dev/mem > print ((unsigned int)virtual_end)-((unsigned int)kernel_vm_end) > This should probably be made into a sysctl so it can be montored > better. > > If you only have a few meg. left it doesn't take many processes to > fork etc. then you machine blows up. The bge driver for example takes > 4M each for the jumbo packet handling. You can recover some of this > memory via loader.conf tunables or bump KVA_PAGES in your kernel > config file. Still once this memory is put into the zone allocator > (vmstat -z) in -stable it is gone from the system even if that bucket > isn't fully used or needed :-( What would you expect to see in the logs on such a scenario? I'm surprised to see nothing. > > Ironically the more memory you put in a system the less you can do with > the system! > > A lot of people are starting to run into this problem since large memory > machines are cheap. Well, I don't think 2gb is large by your standards? > > Doug A. -- -Jim
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