Solving time drift problem on Ubuntu VMWare Guest

I have an Ubuntu VMWare guest, and having trouble with time drift.
After a bit twiddling with ntp synchronization and still getting unacceptable time drift,
finally I read a post in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=471784 :


From: Kazuhiro NISHIYAMA 
To: 471784@bugs.debian.org
Subject: Please recommends open-vm-source
Date: Fri, 28 Mar 2008 21:13:22 +0900
I had a same problem, and resolved following commands:

* sudo aptitude purge open-vm-tools
* sudo reboot
* sudo aptitude install open-vm-source
* pager /usr/share/doc/open-vm-source/README.Debian
* sudo module-assistant prepare open-vm
* sudo module-assistant auto-install open-vm
* sudo aptitude install open-vm-tools
* sudo reboot

I done the steps above, and it seems to work perfectly.
Oh, I didn't do the reboot parts nor the pager one.

EDIT: Seems that its not enough. I have a AMD Phenom x4 CPU, which have some anomalies in regard to CPU clock speed.
The problem is, the CentOS 4.6 Host detected that the CPU have clock speed 1100MHz, in reality the CPU have 2200MHz clock. So, imitating this post, I must tell VMware server the real maximum clock:

vi /etc/vmware/config

edit the file so it resembles these lines:

host.cpukHz = 2200000
host.noTSC = "TRUE"
ptsc.noTSC = "TRUE"


And make sure ntpd runs to handle the small drifts that still occurs.

Comments

Post a Comment

Popular posts from this blog

Long running process in Linux using PHP

Background To do stuff, I usually create web-based applications written in PHP. Sometimes we need to run something that takes a long time, far longer than the 10 second psychological limit for web pages. A bit of googling in stack overflow found us this  http://stackoverflow.com/questions/2212635/best-way-to-manage-long-running-php-script , but I will tell the similar story with a different solution. One of the long running tasks that need to be run is a Pentaho data integration transformation. Difficulties in long running PHP scripts I encountered some problems when trying to make PHP do long running tasks : PHP script timeout. This could be solved by running set_time_limit(0); before the long running tasks. Memory leaks. The framework I normally use have a bit of memory issues, this can be solved either by patching the framework (ok, it is a bit difficult to do, but I did something similar in the past ) or splitting the data to process into several batches. And if you
Read more

Reverse Engineering Reptile Kernel module to Extract Authentication code

Image
 This time I will show how to (partially) reverse engineer a linux kernel module. The linux kernel module is larger than usual kernel module because it is actually a Reptile-based rootkit dropped by some hacker.  Part 1. Get basic module information First we gather basic module info by using modinfo : [root@lb lkrg-0.9.1]# modinfo falc0n filename:       /lib/modules/3.10.0-1127.10.1.el7.x86_64/kernel/sdc/falc0n.ko intree:         Y license:         GPL retpoline:       Y rhelversion:     7.8 srcversion:     81F508029A53F7490CCDB44 depends:         vermagic:       3.10.0-1127.10.1.el7.x86_64 SMP mod_unload modversions   We could also refer to the kernel module file not yet installed in the OS : [root@lb lkrg-0.9.1]# file falc0n.ko falc0n.ko: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), BuildID[sha1]=1bde6abf4732eb620983032a47fbcf07689ece11, not stripped [root@lb lkrg-0.9.1]# modinfo falc0n.ko filename:       /root/lkrg-0.9.1/falc0n.ko intree:         Y license:         GPL retp
Read more

SAP System Copy Lessons Learned

Image
Background Earlier this year I was part of a team that does System Copy for a 20 terabyte plus SAP ERP RM-CA System. And just now I am involved in doing two system copy in just over one week, for much lesser amount of data. I think I would note some lessons learned from the experience in this blog. For the record, we are migrating from HP/UX and AIX to Linux x86 platform. Things that go wrong First, following the System Copy guide carefully is quite a lot of work - mainly because some important stuff are hidden in references in the guide. And reading a SAP note that are referenced in another SAP note, that are referenced in Installation Guide.. is a bit too much. Let me describe what thing goes wrong. VM Time drift The Oracle RAC Cluster have time drift problem, killing one instance when the other is shutting down. The cure for our VMWare-based Linux database server is hidden in SAP Note 989963 "Linux VMWARE Timing", which is basically add a tinker panic 0 in the
Read more