I am having great difficulty to maintain guest OS time. Here
is my environment.
Hardware: Intel Woodcrest processor.
Xen: 3.0.3
Xen OS: Red Hat Enterprise 4 Update 3, x86_64 version
Guest OS: configuration is pretty standard. Please see the
end of email.
Guest OS: Red Hat Enterprise 4 Update 3, x86_64, with
everything installed, ntpd not running.
/proc/sys/xen/independent_wallclock = 0
/proc/sys/xen/permitted_clock_jitter = 10000000
In just 2 days 19 hours, the clock is off by more than 10
hours (faster). So, the time has completely gone crazy.
In the dmesg, there is one line is telling me the time
source is not reliable. Maybe the time emulation on Xen is not reliable at all.
>>>Your time source seems to be instable or some
driver is hogging interupts
I have tried to change independent_wallclock to 1 and started
ntpd and it did not help. The ntpd seems refused to synchronize with a reliable
time source. I am not really good at debugging ntpd. But, the ntpq/association is
telling me either the client itself is rejecting the time source or the time
source is rejecting the client. I think it is the first one.
[root@scnbemux050 ~]# ntpq
ntpq> associations
ind assID
status conf reach auth condition last_event cnt
===========================================================
1 52908 9014 yes
yes none reject reachable 1
2 52909 9014 yes
yes none reject reachable 1
3 52910 9014 yes
yes none reject reachable 1
I installed RH EL4 update 3, x86 version of OS on the same
Xen machine and I did NOT see the problem, at least ntpd worked, even thought
frequent (large) time adjustment is needed.
Does anyone have encountered this problem? If you do, how did
you solve the problem?
Thanks
Sam
# -*- mode: python; -*-
#============================================================================
# Python configuration setup for 'xm create'.
# This script sets the parameters used when a domain is
created using 'xm create'.
# You use a separate script for each domain you want to
create, or
# you can set the parameters for the domain on the xm
command line.
#============================================================================
import os, re
arch = os.uname()[4]
if re.search('64', arch):
arch_libdir = 'lib64'
else:
arch_libdir = 'lib'
#----------------------------------------------------------------------------
# Kernel image file.
kernel = "/usr/lib/xen/boot/hvmloader"
# The domain build function. HVM domain uses 'hvm'.
builder='hvm'
# Initial memory allocation (in megabytes) for the new
domain.
#
# WARNING: Creating a domain with insufficient memory may
cause out of
#
memory errors. The domain needs enough memory to boot kernel
# and
modules. Allocating less than 32MBs is not recommended.
memory = 4096
# Shadow pagetable memory for the domain, in MB.
# Should be at least 2KB per MB of domain memory, plus a few
MB per vcpu.
shadow_memory = 64
# A name for your domain. All domains must have different
names.
name = "el4u3_64"
# 128-bit UUID for the domain. The default behavior is
to generate a new UUID
# on each call to 'xm create'.
#uuid = "06ed00fe-1162-4fc4-b5d8-11993ee4a8b9"
#-----------------------------------------------------------------------------
# the number of cpus guest platform has, default=1
vcpus=4
# enable/disable HVM guest PAE, default=0 (disabled)
pae=1
# enable/disable HVM guest ACPI, default=0 (disabled)
acpi=1
# enable/disable HVM guest APIC, default=0 (disabled)
apic=1
# List of which CPUS this domain is allowed to use, default
Xen picks
#cpus =
"" # leave to Xen to
pick
#cpus =
"0" # all vcpus run on CPU0
#cpus = "0-3,5,^1" # run on cpus 0,2,3,5
# Optionally define mac and/or bridge for the network
interfaces.
# Random MACs are assigned if not given.
#vif = [ 'type=ioemu, mac=00:16:3e:00:00:11, bridge=xenbr0,
model=ne2k_pci' ]
# type=ioemu specify the NIC is an ioemu device not netfront
vif = [ 'type=ioemu, mac=00:16:3e:00:00:11, bridge=xenbr0,
model=pcnet' ]
#----------------------------------------------------------------------------
# Define the disk devices you want the domain to have access
to, and
# what you want them accessible as.
# Each disk entry is of the form phy:UNAME,DEV,MODE
# where UNAME is the device, DEV is the device name the
domain will see,
# and MODE is r for read-only, w for read-write.
disk = [ 'phy:/dev/sdb1,ioemu:hda,w', ',hdc:cdrom,r' ]
#----------------------------------------------------------------------------
# Configure the behaviour when a domain exits. There
are three 'reasons'
# for a domain to stop: poweroff, reboot, and crash.
For each of these you
# may specify:
#
#
"destroy", meaning that the
domain is cleaned up as normal;
#
"restart", meaning that a
new domain is started in place of the old
#
one;
#
"preserve", meaning that no
clean-up is done until the domain is
#
manually destroyed (using xm destroy, for example); or
# "rename-restart", meaning that the
old domain is not cleaned up, but is
#
renamed and a new domain started in its place.
#
# The default is
#
#
# on_reboot = 'restart'
# on_crash = 'restart'
#
# For backwards compatibility we also support the deprecated
option restart
#
# restart = 'onreboot' means
#
on_reboot = 'restart'
#
on_crash = 'destroy'
#
# restart = 'always' means
#
on_reboot = 'restart'
#
on_crash = 'restart'
#
# restart = 'never' means
#
on_reboot = 'destroy'
#
on_crash = 'destroy'
#
#on_reboot = 'restart'
#on_crash = 'restart'
#============================================================================
# New stuff
device_model = '/usr/' + arch_libdir + '/xen/bin/qemu-dm'
#-----------------------------------------------------------------------------
# boot on floppy (a), hard disk (c) or CD-ROM (d)
# default: hard disk, cd-rom, floppy
boot="dac"
#-----------------------------------------------------------------------------
# write to temporary files instead of disk image files
#snapshot=1
#----------------------------------------------------------------------------
# enable SDL library for graphics, default = 0
sdl=0
#----------------------------------------------------------------------------
# enable VNC library for graphics, default = 1
vnc=1
#----------------------------------------------------------------------------
# address that should be listened on for the VNC server if
vnc is set.
# default is to use 'vnc-listen' setting from
/etc/xen/xend-config.sxp
#vnclisten="127.0.0.1"
#----------------------------------------------------------------------------
# set VNC display number, default = domid
#vncdisplay=1
#----------------------------------------------------------------------------
# try to find an unused port for the VNC server, default = 1
#vncunused=1
#----------------------------------------------------------------------------
# enable spawning vncviewer for domain's console
# (only valid when vnc=1), default = 0
vncconsole=1
#----------------------------------------------------------------------------
# no graphics, use serial port
#nographic=0
#----------------------------------------------------------------------------
# enable stdvga, default = 0 (use cirrus logic device model)
stdvga=0
#-----------------------------------------------------------------------------
# serial port re-direct to pty deivce,
/dev/pts/n
# then xm console or minicom can connect
serial='pty'
#-----------------------------------------------------------------------------
# enable sound card support,
[sb16|es1370|all|..,..], default none
#soundhw='sb16'
#-----------------------------------------------------------------------------
# set the real time clock to local time
[default=0 i.e. set to utc]
#localtime=1
#-----------------------------------------------------------------------------
# start in full screen
#full-screen=1
#-----------------------------------------------------------------------------
# Enable USB support (specific devices specified
at runtime through the
#
monitor window)
#usb=1
# Enable USB mouse support (only enable one of
the following, `mouse' for
#
PS/2 protocol relative mouse, `tablet' for
#
absolute mouse)
#usbdevice='mouse'
#usbdevice='tablet'
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