Red Hat Bugzilla – Bug 79078
Machine lock up when using NFS
Last modified: 2015-01-04 17:02:10 EST
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Description of problem:
I have two Linux boxes. A single processor p133 on RH7.1 and a dual processor
p133 running RH7.3. A job on the RH7.1 box mount a directory on the RH7.3 SMP
box and copies any changed files, then unmounts. At some point, the RH7.3 SMP
box locks up, no console no ping no ftp or telnet.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.mount a directory from RH71 to RH73 SMP
2.use a "cp -pu" to copy changed files
3.wait for the target machine to die
Actual Results: After a period of time, could be 5 minutes could be 20, the
SMP box ceases to respond to all external stimuli.
Expected Results: The job should finish after an hour or so and all is well
with the world.
There does not appear to be an error message, I think it is such a complete
halt that Linux is not getting chance to write an error to the message log.
If the NFS services are disabled then the machine seems to stay up quite
happily. The copy job has worked without modification for many months when the
target machine was a RH6.2 single processor box.
question: what exact kernel is running on the hanging box?
also can you try adding "nmi_watchdog=1" to the kernel commandline of the
hanging box (that's the vmlinuz line in /boot/grub/grub.conf). Doing this will
make the kernel try to detect deadlocks and print a backtrace if it detects one.
Thanks for such a rapid response. The machines are at home, I will provide the
requested details tomorrow.
Here is my grub.conf
password --md5 $1$cF\V1.BG$556CULbW1ITuEhGZ4.gLO1
title Red Hat Linux (2.4.18-3smp)
kernel /vmlinuz-2.4.18-3smp ro root=/dev/hda6 noapic
title Red Hat Linux-up (2.4.18-3)
kernel /vmlinuz-2.4.18-3 ro root=/dev/hda6
I tried running with nmi-watch=1
Dec 5 18:22:27 puntus kernel: Default MP configuration #6
Dec 5 18:22:27 puntus kernel: Processor #0 Pentium(tm) APIC version 16
Dec 5 18:22:27 puntus kernel: Processor #1 Pentium(tm) APIC version 16
Dec 5 18:22:27 puntus kernel: I/O APIC #2 Version 16 at 0xFEC00000.
Dec 5 18:22:27 puntus kernel: Processors: 2
Dec 5 18:22:27 puntus kernel: Kernel command line: ro root=/dev/hda6 noapic
Dec 5 18:22:27 puntus kernel: Initializing CPU#0
Dec 5 18:22:27 puntus kernel: Detected 133.610 MHz processor.
I was tailing the messages file when it crashed
gort.squirrelsoft:1005 for /backup (/backup)
Dec 5 18:28:32 puntus rpc.mountd: authenticated mount request from
gort.squirrelsoft:1008 for /backup (/backup)
Dec 5 18:28:51 puntus rpc.mountd: authenticated mount request from
gort.squirrelsoft:762 for /backup (/backup)
Dec 5 18:38:53 puntus su(pam_unix): session opened for user news by
Dec 5 18:38:54 puntus su(pam_unix): session closed for user news
No trace was found (where would it be?)
I also ran in single processor mode but it still hung.
noapic and the nmi watchdog are exclusive ;(
If i don't run noapic, i wold normally get lost interupt errors relating to the
hard disks. Will nmi watchdog still stop that happining or am I stucj now?
I have given up on this one. I have reverted to the old single processor box.
Thanks for your time but let's not waste any more effort. Cheers, Mark.