Problem Connecting to the Server

Installing, Configuring, Troubleshooting server daemons such as Web and Mail
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Reza
Posts: 1
Joined: 2014/10/19 13:53:10

Problem Connecting to the Server

Post by Reza » 2014/10/19 14:33:01

Hi,
I am new to the linux and I am struggling with an error.
When I want to connect to the main server from my PC, I receive the following Error inside the terminal repetitively:

Message from syslogd@ at Sun Oct 19 23:21:35 2014 ...
fs kernel: Dazed and confused, but trying to continue

Message from syslogd@ at Sun Oct 19 23:21:35 2014 ...
fs kernel: Uhhuh. NMI received for unknown reason 20.

Message from syslogd@ at Sun Oct 19 23:21:35 2014 ...
fs kernel: Do you have a strange power saving mode enabled?

Message from syslogd@ at Sun Oct 19 23:21:35 2014 ...
fs kernel: Dazed and confused, but trying to continue

Message from syslogd@ at Sun Oct 19 23:21:35 2014 ...
fs kernel: Uhhuh. NMI received for unknown reason 30.

The main server OS is Centos 5.8. Would some one please tell me where the error is coming from and how to solve it?

Supplementary Information:

I also checked the clusters inside the main server and one of them had this error message in /var/spool/mail/tool:
Unmatched Entries
Device: /dev/hdb, packet device [this device CD/DVD] not smart capable
Device /dev/sda: using ' -d sat' for ATA disk behind SAT layer.

I do not know this is relevant to the current problem or not.

Best Regards,
Reza

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TrevorH
Site Admin
Posts: 33202
Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: Problem Connecting to the Server

Post by TrevorH » 2014/10/19 19:02:36

Check the rest of the kernel messages via the dmesg comand and/or look in /var/log/messages for more clues. Immediately I'd guess you have a hardware problem but nothing is certain.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

aks
Posts: 3073
Joined: 2014/09/20 11:22:14

Re: Problem Connecting to the Server

Post by aks » 2014/10/20 16:24:24

So you don't say if this is a VM or not, so I assume it's running on hardware.

Generally it *sounds* like some of the RAM (including but not limited to SATA, RAID, main memory, graphics memory) somewhere in the system is still in sleep mode, when it should be awake.

If your kernel is out of date - update it (this is the most likely cause).


Check your hardware - run some good hardware diagnostics programs multiple times and see if there are any errors (the next most likely cause).

If it's an HP or Dell node with their RAID (Smart Array in HP's case) controller you probably need to upgrade the RAID firmware. There's known bugs regardless of the write cache policy on the RAID controller, the one I most remember is an ASPM on the P410i whereby if you appeneded pcie_aspm=off to grub.conf & reboot, the messages disappear, but there have been many problems with those RAID products.

An NMI is a non maskable interrupt, which means hardware (usually) is telling us something that the source systems thinks is so important we can not delay or ignore it. This means it's usually quite important. So it could be a problem with timings. If you disable NMI watchdog (append nmi_watchdog=0 to grub.conf) and switch off the HPET (high precision event timer) (append nohpet in grub.conf) and reboot, do the messages disappear? Mind doing this long term is probably a bad idea.

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