Date: Sat, 22 Dec 2001 20:59:00 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Nils Holland <nils@tisys.org> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: NFS problems in 4.5-PRERELEASE Message-ID: <200112230459.fBN4x0u99894@apollo.backplane.com> References: <20011223005213.A57692@tisys.org>
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:...
:I copied /usr/src, /usr/obj and /usr/ports from one machine to another via
:NFS. src and obj are fairly normal, ports included about 300 MB worth of
:distfiles besides the ports skeleton itself.
:
:Now, the NFS copy of src and ports does *always* work (I tried 10 times),
:while copying ports seems to crash my NFS client in 2 out of three cases. The
:exact panic message I get (which is probably not that useful by itself, but
:I'll post it anyway) is this:
:
:Fatal Trap 12: Page fault while in kernel mode
:fault virtual address = 0xe8
:fault code = supervisor read, page not present
:...
This kinda sounds like a memory allocation failure in the kernel,
perhaps the kernel is running out of KVM. I have a couple of
recommendations and questions.
* post your kernel config
* post your /var/run/dmesg.boot output
In your kernel config, assuming you know how to compile up kernels,
add the following options, config, compile, & install a new kernel.
options DDB
options INVARIANTS
options INVARIANT_SUPPORT
Now when it crashes you should get a DDB> prompt. From that prompt
you should do a 'trace' command (and then 'panic' once or twice to
panic the machine normally).
Other things to observe while you are running your tests:
vmstat -m
vmstat -z
systat -vm 1 (observe number of vnodes)
Basically you are looking for kernel memory pools that might
be getting blown out by the problem.
-Matt
Matthew Dillon
<dillon@backplane.com>
:instruction pointer = 0x8:0xc01b61cc
:stack pointer = 0x10:0xe1c73cb8
:frame pointer = 0x10:0xe1c73cd4
:code segment = base 0x0, limit 0xfffff, type 0x1b
: DPL 0, pres 1, def32 1, gran 1
:processor eflags = interrupt enabled, resume, IOPL = 0
:current process = 367 (cp)
:interrupt mask = none
:trap number = 12
:panic: page fault
:
:And now it gets interesting: This crash does *not* occur randomly, but as
:my tests have shown, it occurs *always* when /usr/ports/japanese/mnews is
:being copied (as shown by cp -v). To prevent misunderstandings, let
:me reword this: The problem seems to occur 2 out of 3 times, but *when* it
:...
:Good night
:Nils
:--
:Nils Holland
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