Keir and others,
Please check the table in the end of the mail below.. is there
hypervisor (boot time) option to make it behave better for ntpd?
-- Pasi
On Sat, Jan 16, 2010 at 11:17:36AM -0800, mail ignored wrote:
> On Thu, Jan 14, 2010 at 8:20 PM, Fajar A. Nugraha <fajar@xxxxxxxxx> wrote:
> >> @ novell say it's xen & ntp
> >> @ ntp say it's novell & xen
> >> @ xen say it's novell & ntp
> >>
>
> > That's why I suggested you use a workaround: use 2.6.18 kernel, either
> > from RHEL or from xen.org :D
> > If this works -> novell problem
> > If this doesn't work -> xen problem
>
> On Sat, Jan 16, 2010 at 5:05 AM, Fajar A. Nugraha <fajar@xxxxxxxxx> wrote:
> > You might want to try latest pv_ops as well
> > (http://wiki.xensource.com/xenwiki/XenParavirtOps), which should be
> > easier to work with Opensuse since the version number is close.
>
> it seems it's _not_ the kernel -- unless there's a coincident kernel
> problem across source/vendor ...
>
> per
> http://lists.xensource.com/archives/html/xen-devel/2009-12/msg01127.html
> http://wiki.xensource.com/xenwiki/XenParavirtOps
> http://wiki.xensource.com/xenwiki/Kernel.org_Linux_on_Xen
>
> cd /home/workspace && rm -rf linux-2.6-xen
> git clone git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git
> linux-2.6-xen
> cd linux-2.6-xen
> make clean
> cp -a .config .config-old
> wget -O .config
> http://pasik.reaktio.net/xen/pv_ops-dom0-debug/config-2.6.31.4-pvops_dom0-x86_64
> make oldconfig
> ...
> Xen PCI Frontend (XEN_PCIDEV_FRONTEND) [N/m/y/?] (NEW) <-- m
> ...
> "IMQ" target support (NETFILTER_XT_TARGET_IMQ) [N/m/?] (NEW) <-- m
> ...
> IMQ (intermediate queueing device) support (IMQ) [M/y/?] (NEW) <-- [enter]
> ...
> Block-device tap backend driver (XEN_BLKDEV_TAP) [N/m/y/?] (NEW) <-- m
> ...
>
> make bzImage
> make modules
> make modules_install
> strip vmlinux -o vmlinux-stripped
> gzip vmlinux-stripped -c > vmlinuz-gzipped
>
> ls -al .config \
> System.map \
> arch/x86/boot/bzImage \
> vmlinux \
> vmlinux-stripped \
> vmlinuz-gzipped
>
> cp -a .config /boot/config-2.6.31.6
> cp -a System.map /boot/System.map-2.6.31.6
> cp -a arch/x86/boot/bzImage /boot/vmlinuz-2.6.31.6
> mkinitrd
> ls -al /boot/*2.6.31.6*
> -rw-r--r-- 1 root root 98510 2010-01-16 03:02 /boot/config-2.6.31.6
> -rw-r--r-- 1 root root 21304611 2010-01-16 04:14 /boot/initrd-2.6.31.6
> -rw-r--r-- 1 root root 1940879 2010-01-16 03:14 /boot/System.map-2.6.31.6
> -rw-r--r-- 1 root root 3751936 2010-01-16 03:14 /boot/vmlinuz-2.6.31.6
>
>
> vi /boot/grub/menu.lst
> ...
> title xen.git
> root (hd0,0)
> kernel /xen.gz loglvl=all loglvl_guest=all dom0_mem=1024M
> vga=gfx-1280x1024x32 console=vga,com1 com1=57600,8n1
> module /vmlinuz-2.6.31.6 root=/dev/VG0/ROOT rootfstype=ext4
> rootflags=journal_checksum resume=/dev/VG0/SWAP nomodeset selinux=0
> SELINUX_INIT=NO vga=0x31a console=tty0 console=xvc0,57600
> module /initrd-2.6.31.6
>
> title xen.git DISABLED
> root (hd0,0)
> kernel /vmlinuz-2.6.31.6 root=/dev/VG_SVR/LV_SVR_DOM0_ROOT
> rootfstype=ext4 rootflags=journal_checksum
> resume=/dev/VG_SVR/LV_SVR_DOM0_SWAP nomodeset showopts splash=silent
> selinux=0 SELINUX_INIT=NO elevator=cfq vga=0x31a console=tty0
> console=ttyS0,57600n8
> module /initrd-2.6.31.6
> ...
>
>
> boot to "xen.git"
>
> uname -a
> Linux test 2.6.31.6 #1 SMP Sat Jan 16 03:14:19 PST 2010 x86_64
> x86_64 x86_64 GNU/Linux
> lsb_release -a
> LSB Version:
> core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64:desktop-4.0-amd64:desktop-4.0-noarch:graphics-2.0-amd64:graphics-2.0-noarch:graphics-3.2-amd64:graphics-3.2-noarch:graphics-4.0-amd64:graphics-4.0-noarch
> Distributor ID: SUSE LINUX
> Description: openSUSE 11.2 (x86_64)
> Release: 11.2
> Codename: n/a
>
> service ntp stop
> rm /etc/adjtime /var/
> rm /var/lib/ntp/drift/ntp.drift
>
> cat << EOF > /etc/sysconfig/clock
> HWCLOCK="--utc"
> SYSTOHC="yes"
> TIMEZONE="America/Los_Angeles"
> DEFAULT_TIMEZONE="US/Pacific"
> EOF
> hwclock --systohc --utc
> service ntp start
>
> sntp clock.isc.org && date && hwclock --utc --show
> 2010 Jan 16 04:37:09.000729 + 1.435060 +/- 0.028944 secs
> Sat Jan 16 04:37:11 PST 2010
> Sat 16 Jan 2010 04:37:11 AM PST -0.345191 seconds
>
> ... (wait ~ 6 hours) ...
>
> date
> Sat Jan 16 11:01:42 PST 2010
> ntpq -p -c rv
> assID=0 status=06c4 leap_none, sync_ntp, 12 events,
> event_peer/strat_chg,
> version="ntpd 4.2.4p8@xxxxxx Mon Dec 28 17:26:30 UTC 2009 (1)",
> processor="x86_64", system="Linux/2.6.31.6", leap=00, stratum=2,
> precision=-20, rootdelay=14.718, rootdispersion=135.995, peer=11390,
> refid=66.220.9.122,
> reftime=cefc89b2.a36f1342 Sat, Jan 16 2010 10:53:38.638, poll=6,
> clock=cefc8b82.7e523feb Sat, Jan 16 2010 11:01:22.493, state=2,
> offset=-115.130, frequency=-500.000, jitter=464.242, noise=29.343,
> stability=154.680
> remote refid st t when poll reach delay offset
> jitter
>
> ==============================================================================
> *clock.fmt.he.ne .PPS. 1 u 29 64 377 21.438 -811.68
> 462.837
> +otc2.psu.edu 129.6.15.29 2 u 7 64 377 109.399 -850.99
> 470.522
> +clock.isc.org .GPS. 1 u 7 64 377 21.440 -854.82
> 468.274
> +clock.sjc.he.ne .CDMA. 1 u 49 64 377 16.889 -780.55
> 469.481
> +zorro.sf-bay.or 216.218.254.202 2 u 59 64 377 20.366 -762.14
> 458.947
> +nist1.aol-ca.tr .ACTS. 1 u 38 64 377 16.260 -795.87
> 463.170
>
> boot to "xen.git DISABLED"
>
> uname -a
> Linux test 2.6.31.6 #1 SMP Sat Jan 16 09:14:19 PST 2010 x86_64 x86_64
> x86_64 GNU/Linux
>
> service ntp stop
> rm /etc/adjtime /var/
> rm /var/lib/ntp/drift/ntp.drift
> service ntp start
>
> ... (wait ~ 10 minutes) ...
> date
> Sat Jan 16 11:15:05 PST 2010
> ntpq -p -c rv
> assID=0 status=0664 leap_none, sync_ntp, 6 events, event_peer/strat_chg,
> version="ntpd 4.2.4p8@xxxxxx Mon Dec 28 17:26:30 UTC 2009 (1)",
> processor="x86_64", system="Linux/2.6.31.6", leap=00, stratum=2,
> precision=-20, rootdelay=22.750, rootdispersion=975.184, peer=43091,
> refid=66.220.9.122,
> reftime=cefc8c7c.35ca466a Sat, Jan 16 2010 11:05:32.210, poll=6,
> clock=cefc8eb9.25103a1f Sat, Jan 16 2010 11:15:05.144, state=3,
> offset=27.534, frequency=0.000, jitter=6.740, noise=16.331,
> stability=0.000
> remote refid st t when poll reach delay offset
> jitter
>
> ==============================================================================
> *clock.fmt.he.ne .PPS. 1 u 4 64 377 18.112 10.541
> 5.892
> +otc2.psu.edu 147.84.59.145 2 u 64 64 377 101.103 12.106
> 8.621
> +clock.isc.org .GPS. 1 u 57 64 377 14.990 4.830
> 9.622
> +clock.sjc.he.ne .CDMA. 1 u 59 64 377 16.503 9.299
> 9.440
> +zorro.sf-bay.or 216.218.254.202 2 u 56 64 377 22.212 6.323
> 11.031
> +nist1.aol-ca.tr .ACTS. 1 u 60 64 377 17.076 14.316
> 9.260
>
> in summary,
>
> kernel OS/distro xen timekeeping
> ------------------------------------- --------------- ------- ------------
> opensuse kernel-default-2.6.31.8-0.1 opensuse 11.2 (n/a) OK
> opensuse kernel-default-2.6.32-41 opensuse 11.2 (n/a) OK
> opensuse kernel-xen-2.6.31.8-0.1 opensuse 11.2 3.4.x NOISY/FAIL
> opensuse kernel-xen-2.6.32-41 opensuse 11.2 3.4.x NOISY/FAIL
> opensuse kernel-xen-2.6.31.8-0.1 opensuse 11.2 4.0.x NOISY/FAIL
> opensuse kernel-xen-2.6.32-41 opensuse 11.2 4.0.x NOISY/FAIL
> xen.git kernel-2.6.31.6 (pvops Dom0) opensuse 11.2 4.0.x NOISY/FAIL
> xen.git kernel-2.6.31.6 opensuse 11.2 (n/a) OK
>
> i.e.,
>
> 3 different kernel versions, from two different vendors, have
> low-noise/accurate timekeeping in NON-xen configs.
>
> boot any of those kernels with either v34x or v40x hypervisor in
> place, and timekeeping suffers from unusably excessive jitter &
> offset.
>
> _______________________________________________
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> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
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