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After 3 days uptime, I can't run top in Linux.

This is x86 Linux Fedora Core 8 running under vmWare under Windows XP.

[root@fc8 ]# uname -a
Linux fc8 #1 SMP Tue Oct 30 13:55:12 EDT 2007 i686 i686 i386 GNU/Linux

ps, uptime works fine.

Anyone have any suggestion on what might be the problem or how to diagnose it?

There is no error message. The "top" command just hangs there.

Also, one other problem I notice at the sametime was that time somecommand gives:

real    0m0.000s
user    0m0.000s
sys     0m0.000s

The somecommand did take a few seconds to execute.

The system time in Linux under vmWare session is corrected. I don't use the ntp to sync time. I have a cron job to sync time with the hwclock --hwtosys command.

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migrated from Dec 3 '09 at 17:26

This question came from our site for professional and enthusiast programmers.

I think you might be more likely to find your answer at – DOK Dec 3 '09 at 17:09
When you go there, be sure to bring with you the error message you're getting, or any information at all as to what actually happens. – qid Dec 3 '09 at 17:11
1 if it's just your personal machine, if it's server (and since it has few days uptime it's probably server) – Phil Dec 3 '09 at 17:15
try running "strace top" to see where top is getting stuck. It may give you some clues. – camh Jan 5 '10 at 8:36

What is the VM's clock showing at these times? It could be something strange in what-ever combination of clock syncing (if any) is going on. If VMWare is slowing the VM's clock a lot to try account for what it thinks is the VM's time getting to far ahead then that might explain time returning a wall-clock time of 0 and top (which takes some readings, waits a second or so, takes some more readings, then updates its display) pausing waiting for the second(s) to tick over.

If the clock does seem to be where is shouldn't be: I find the most reliable way to keep VM clocks accurate is to make sure VMWare's clock sync options are off and use NTP with tinker panic 0 at the top of the config file.

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David, I use this to sync time instead of ntp. I notice the hwclock in Linux always provide the right time. I have issue with company firewall blocking the NTP. [root@fc8 pogo]# crontab -l # hourly to sync the hwclock 0-59 * * * * /sbin/hwclock --hctosys # Work day sync of NTP server at 11 am * 11 * * 1,2,3,4,5 /usr/sbin/ntpdate – tony-p-lee Dec 3 '09 at 20:07
The time in Linux under vmWare is correct. – tony-p-lee Dec 3 '09 at 20:07

Question: Did you use a newly woken up vmware session? I noticed that the clock sometimes only restores to the correct time after something like a minute, although it feels a lot longer :-(. Did you check your (ntp?) time-service?

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You could try installing and using htop -

How log did you leave top sitting there? Did you give it 10 minutes, for example?

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This time, I reboot the system. Previously, I have seen it hanged there for at lease a few hours. Reboot Linux in vmWare does solve the problem. – tony-p-lee Dec 4 '09 at 6:58
Just did a yum install htop, it is very nice. BTW, I might be able to use strace to track down deeper, will try that when I see it happen again. Thanks for suggestion and inspiration... – tony-p-lee Dec 4 '09 at 7:30

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