My KVM Forum 2015 talk: New qemu technology used in virt-v2v

All KVM Forum talks can be found here.

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Vote for Pino & Luigi Toscano’s libguestfs talk at the Openstack Summit

https://www.openstack.org/summit/tokyo-2015/vote-for-speakers/presentation/5066

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Why has the libguestfs appliance grown by 281 MB?

a.k.a guestmount + filelight are awesome!

Click to see the full image

Screenshot_2015-07-23_14-22-50

If you want to reproduce the same diagrams yourself, just do:

$ mkdir /tmp/mp
$ guestmount --ro \
    -a /var/tmp/.guestfs-1000/appliance.d/root \
    -m /dev/sda /tmp/mp
$ filelight /tmp/mp

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Stratum-1 NTP server, part 3

After about 24 hours it has settled down nicely.

# ntpq -c peers
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
oPPS(0)          .PPS.            0 l    4   16  377    0.000    0.010   0.002
*ptbtime1.ptb.de .PTB.            1 u   55   64  177   51.291    1.112   1.450
+uno.alvm.me     103.7.151.4      2 u    8   64  377   19.008    3.451   0.819
-time-a.as43289. 162.23.41.56     2 u   49   64  177   73.242   14.530   4.915
-95-65-94-223.st 193.226.65.36    2 u    5   64  377   73.743    7.543   0.509
-hemel-hempstead 193.67.79.202    2 u   12   64  377   19.829    3.720   0.551
-time.rdg.uk.as4 85.25.105.105    2 u   11   64  377   19.924    0.677   0.491
+time.dan.me.uk  140.203.204.77   2 u   40   64  177   62.218    3.616   0.372
-dns2-ha.uk.syra 83.170.75.28     4 u   11   64  377   19.365    4.274   0.652
# ntpq -c rv
associd=0 status=011d leap_none, sync_pps, 1 event, kern,
version="ntpd 4.2.6p5@1.2349-o Sat Jul  4 15:08:48 UTC 2015 (1)",
processor="armv7l", system="Linux/3.18.11-v7+", leap=00, stratum=1,
precision=-20, rootdelay=0.000, rootdisp=0.394, refid=PPS,
reftime=d943cdae.7978b6bf  Sun, Jul  5 2015 16:37:18.474,
clock=d943cdb8.e8908274  Sun, Jul  5 2015 16:37:28.908, peer=2027, tc=4,
mintc=3, offset=0.010, frequency=-3.056, sys_jitter=0.002,
clk_jitter=0.000, clk_wander=0.002

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Stratum-1 NTP server, part 2

20150704_151027

It took me about an hour to work out that I had the board plugged in the wrong way around, and that’s why nothing worked. My excuse is we’re in the middle of a heatwave at the moment ….

Anyway, the picture above is how you’re supposed to do it.

The R-Pi is running standard Raspbian, and the rest of the software setup can be found on this page update: this is the right link.

The board almost immediately finds a timepulse.

After running for a little while:

# ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
xPPS(0)          .PPS.            0 l   13   16  377    0.000   -7.334   0.159
xipv6test.te.net 195.138.80.34    3 u   51   64  377   72.959   -1.776   0.711

(and yes I know it says Stratum 0 …)

The output is saying that the GPS source (PPS) has an offset of 7.3ms from the internal clock. The stratum 3 internet source is 1.8ms from the internal clock (but note the internal clock is likely wrong). The delay (round trip?) to the local clock is 0, and the delay from the internet source is 73ms.

They are both currently marked as “x” meaning “falsetickers”. I think ntpd needs a bit longer to decide to use the GPS source.

# ntpq -c rv
associd=0 status=0018 leap_none, sync_unspec, 1 event, no_sys_peer,
version="ntpd 4.2.6p5@1.2349-o Sat Jul  4 15:08:48 UTC 2015 (1)",
processor="armv7l", system="Linux/3.18.11-v7+", leap=00, stratum=1,
precision=-20, rootdelay=0.000, rootdisp=86.994, refid=PPS,
reftime=d942771e.6dc41fc9  Sat, Jul  4 2015 16:15:42.428,
clock=d9427c3a.d8cd27b8  Sat, Jul  4 2015 16:37:30.846, peer=0, tc=4,
mintc=3, offset=0.003, frequency=0.000, sys_jitter=0.116,
clk_jitter=3.476, clk_wander=0.000

Update: After reading this Red Hat article and this ntp.org document, I realized my mistake was having only two clocksources, which is the worst configuration for ntpd. Adding a bunch more sources makes it better:

# ntpq -c peers
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
oPPS(0)          .PPS.            0 l   16   16  377    0.000   -0.094   0.008
*server.104media 193.67.79.202    2 u   30   64  377   29.748    3.890   0.610
-ns2.vnet.sk     95.47.106.34     3 u   29   64  377   50.536    0.622   0.268
+nero.grnet.gr   .GPS.            1 u   27   64  377   71.089    4.371   0.619
-frankfurt1.firs 85.214.240.94    3 u   26   64  377   35.655    5.620   0.541
-time.rdg.uk.as4 84.2.44.19       3 u   40   64  377   19.761    3.070   0.197
-ntp1.ic.net.uk  158.43.128.33    2 u   43   64  377   18.153    3.659   0.176
-ns0.luns.net.uk 158.43.192.66    2 u   48   64  377   25.761    3.648   0.219
+ntppub.le.ac.uk 158.43.192.66    2 u   47   64  377   21.566    3.783   0.520

However for some reason it only works when I restart the NTP server a minute after boot. It may be that the kernel PPS device isn’t ready when the NTP server starts first time. In any case, I added this to /etc/rc.local:

( sleep 60 ; service ntp restart ) &

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Stratum-1 NTP server, part 1

I’m following the instructions here and here to try and make a Stratum-1 NTP server using GPS and a Raspberry Pi 2. If this works, I should have a very accurate NTP server for a very reasonable amount of money.

20150704_134742

I ordered the Raspberry Pi 2 from Amazon, and the other parts from HAB Supplies in the UK. The total cost (prices include tax) was:

Raspberry Pi 2 £29.99
GPS expansion board £35.99
Antenna and cable £41.99
Postage £5.52
Total £113.49

Edit: I already had a spare 32GB SD card and power supply. If you don’t have those already, you’d need to buy them too.

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AMD previewing Seattle at the Red Hat Summit

The announcement is here, and according to that announcement the development boards will be available in “second half” 2015.

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