[libvirt-users] How to optimize for IBM db2?
by Basin Ilya
Hi.
I have performance problems with IBM DB2 10.5 server on KVM guest:
[db2inst1@wc8ws-auth ~]$ time db2 create db test
DB20000I The CREATE DATABASE command completed successfully.
real 7m46.155s
user 0m0.022s
sys 0m0.027s
It takes 30 seconds to create a database on an image mounted with -oloop.
I think it's because db2 uses O_DIRECT to ensure consistency. I also think that O_DIRECT is not propagated to host with default cache modes in VM settings. The real problem is: when guest writes data in small blocks, host CPU becomes a bottleneck.
I hava a relatively old 24-core Xeon. Host `top` shows 130% CPU usage by qemu-kvm, when I run the following command:
[root@wc8ws-auth ~]# </dev/zero timeout -sINT 30s dd iflag=fullblock oflag=direct conv=notrunc of=./bigfile bs=8192
140384+0 records in
140384+0 records out
1150025728 bytes (1.2 GB) copied, 29.9992 s, 38.3 MB/s
I tried all buses, cache modes and IO modes; "Cache mode=none" is slower, others are almost equal.
I moved from image file to LVM. This raised the speed from 16M to 38M.
I also tried VirtualBox, but it's neither faster, nor slower, and it eats CPU too.
--
--------------------------------------------------------------------------------
Kind regards,
Ilya Basin
software engineer
Reksoft
Skype: basin_ilya
phone +7(812)324-24-40*553
8 years, 7 months
[libvirt-users] DBus API for libvirt
by sbaugh＠catern.com
Hello,
For a variety of reasons I am interested in a D-Bus interface for
libvirt.
Primarily for use with http://cockpit-project.org/ for which it
would be very easy to write a web interface for libvirt, given a D-Bus
interface for libvirt, but writing using the raw libvirt RPC protocol
would require writing a new Javascript library for parsing/encoding that
protocol. But there are other nice features of a D-Bus interface for
libvirt, too.
Does a D-Bus interface for libvirt exist?
Thanks!
8 years, 7 months
[libvirt-users] Clone VM with saved state
by Michael Ravits
Hi,
My use case involves creating duplicates of saved virtual machines.
Tried with virt-manager and with virsh but so far it seems like this case
is not supported by these tools.
Does anyone know how I could achieve the above?
Thanks,
Michael
8 years, 7 months
Re: [libvirt-users] [Bug 1325687] network type="ethernet" not supported with LXC
by abhishek jain
Hi Team
I'm trying to launch LXC VM with libvirt 1.2.12 having commit
*22cff52a2b8e06c913b1f97767e5d3**90fb17fc3b *with below XML configuration..
<domain type="lxc">
<uuid>64c48da2-e318-4085-8b88-c980aab4de34</uuid>
<name>test</name>
<memory>524288</memory>
<vcpu>1</vcpu>
<os>
<type machine="virt">exe</type>
<cmdline>root=/dev/ram0 rw console=ttyAMA0 rootwait
earlyprintk</cmdline>
<init>/bin/sh</init>
</os>
<clock offset="utc"/>
<devices>
<file/>
<interface type='ethernet'>
<mac address='02:74:ff:9d:52:f5'/>
<script path=''/>
<target dev='tap74f2-f5'/>
</interface>
<console type="pty"/>
</devices>
</domain>
I'm getting following errors while launching LXC VM using above XML file..
virsh -c lxc: define lxc.xml
virsh -c lxc: start
test
error: Failed to start domain test
error: internal error: guest failed to start: /usr/lib/libvirt/libvirt_lxc:
option '--veth' requires an argument
syntax: /usr/lib/libvirt/libvirt_lxc [OPTIONS]
Options
-b, --background
-n NAME, --name NAME
-c FD, --console FD
-v VETH, --veth VETH
-s FD, --handshakefd FD
-S NAME, --security NAME
-h, --help
Unknown failure in libvirt_lxc startup
Please help me regarding this.
--Thanks
Abhishek Jain
On Mon, Apr 11, 2016 at 3:35 AM, <bugzilla(a)redhat.com> wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=1325687
>
> Cole Robinson <crobinso(a)redhat.com> changed:
>
> What |Removed |Added
>
> ----------------------------------------------------------------------------
> Status|NEW |CLOSED
> CC| |crobinso(a)redhat.com
> Resolution|--- |CURRENTRELEASE
> Last Closed| |2016-04-10 18:05:06
>
>
>
> --- Comment #1 from Cole Robinson <crobinso(a)redhat.com> ---
> ethernet support was actually enabled for lxc via this commit:
>
> commit 22cff52a2b8e06c913b1f97767e5d390fb17fc3b
> Author: Anirban Chakraborty <abchak(a)juniper.net>
> Date: Tue Nov 18 15:55:48 2014 -0800
>
> network: Add network bandwidth support to ethernet interfaces
>
>
> Which looks like libvirt v1.2.10 or v1.2.11
>
> --
> You are receiving this mail because:
> You are on the CC list for the bug.
> You reported the bug.
8 years, 7 months
[libvirt-users] CentOS 6 and 1.3.3
by Brian Rak
libvirt 1.3.3 seems to have introduced some kind of issue on CentOS 6
(no systemd). After upgrading, libvirt would take an incredibly long
time to get to a state where it would actually respond to a simple
'virsh list' command.
Looking at verbose output showed this repeating at exactly 30s intervals
2016-04-12 19:40:57.142+0000: 14929: info :
virEventPollDispatchHandles:507 : EVENT_POLL_DISPATCH_HANDLE: watch=1
events=1
2016-04-12 19:40:57.142+0000: 14929: info : virEventPollRunOnce:641 :
EVENT_POLL_RUN: nhandles=116 timeout=-1
2016-04-12 19:40:57.143+0000: 15223: info : virObjectRef:296 :
OBJECT_REF: obj=0x7fb944181bc0
2016-04-12 19:40:57.144+0000: 15223: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb944181bc0
2016-04-12 19:40:57.157+0000: 15223: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb944253020
2016-04-12 19:40:57.157+0000: 15223: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb944309450
2016-04-12 19:40:57.157+0000: 15223: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb94400ca90
2016-04-12 19:41:27.147+0000: 15224: info : virDBusCall:1577 :
DBUS_METHOD_REPLY: 'org.freedesktop.DBus.ListActivatableNames' on
'/org/freedesktop/DBus' at 'org.freedesktop.DBus'
2016-04-12 19:41:27.148+0000: 15224: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb94400ca90
2016-04-12 19:41:27.148+0000: 15224: info : virObjectRef:296 :
OBJECT_REF: obj=0x7fb94400ca90
2016-04-12 19:41:27.148+0000: 15224: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb94400ca90
2016-04-12 19:41:27.148+0000: 15224: info : virObjectRef:296 :
OBJECT_REF: obj=0x7fb94400ca90
2016-04-12 19:41:27.151+0000: 15224: info : virObjectUnref:259 :
OBJECT_UNREF: obj=0x7fb94400ca90
2016-04-12 19:41:27.151+0000: 15224: info : virObjectRef:296 :
OBJECT_REF: obj=0x7fb860000e30
2016-04-12 19:41:27.151+0000: 15224: info : virEventPollUpdateHandle:152
: EVENT_POLL_UPDATE_HANDLE: watch=58 events=15
2016-04-12 19:41:27.151+0000: 15224: info : qemuMonitorSend:1005 :
QEMU_MONITOR_SEND_MSG: mon=0x7fb860000e30
msg={"execute":"query-status","id":"libvirt-7"}
fd=-1
Looking at the dbus src, there's a 30s timeout defined here:
src/util/virdbus.c:# define VIR_DBUS_METHOD_CALL_TIMEOUT_MILLIS 30 * 1000
So, for some reason libvirt is trying to call a dbus method before every
KVM instance start. This leads to absurdly long startup times. This
behavior was not present in 1.3.1.
My workaround was to just recompile with '--with-firewalld=no
--with-dbus=no', which seems to have worked. There's not really
anything useful for libvirt to be talking to via dbus (in our
environment), so no big loss there.
8 years, 7 months
[libvirt-users] add external access to routed dnsmasq
by Jeff
I have created a routed virtual network. From within the routed net,
DNS requests to the dnsmasq interface virbr2 work fine.
On the libvirt host, DNS requests to the dnsmasq interface virbr2 work fine.
I would like to allow external hosts, on the same network as the
libvirt host, to query the dnsmasq interface. However external DNS
queries to the virbr2 interface time out.
The iptables firewall for this interface and port look clear.
question: How to enable external dns queries to my routed virtual network?
my config:
dnsmasq-2.66-14.el7_1.x86_64
libvirt-1.2.17-13.el7_2.3.x86_64
thanks,
Jeff
8 years, 7 months
[libvirt-users] Duplicate ID 'pci' for device
by Nerijus Baliunas
Hello,
I use fedora-virt-preview repo and it recently updated to
qemu-2.6.0-0.1.rc1.fc23.x86_64 and libvirt-1.3.3-1.fc23.x86_64.
Now my arm VM does not start:
Error starting domain: internal error: process exited while
connecting to monitor: qemu-system-arm:
-device pci-bridge,chassis_nr=2,id=pci,bus=pci,addr=0x1:
Duplicate ID 'pci' for device
I uploaded VM xml file to http://paste.fedoraproject.org/353914/46037204
Regards,
Nerijus
8 years, 7 months
[libvirt-users] virsh dump
by Leekitty
Hi
I want to use “virsh dump ”to only get the memory of a domain,but I do not know the image format 。
Questions:
How can I get the memory by using “virsh dump”
Wen Lee
8 years, 7 months
[libvirt-users] create a network such as default network
by Mohsen Pahlevanzadeh
Dear All,
When user uses `virsh net-define xmlfile` , User only define an xml file
in `/etc/libvirt/qemu/networks`.
I created an uuid and another bridge in related xml file. But I need to
create the following files for my network:
`default.addnhosts default.conf default.hostsfile virbr0.status`
Question is , can I create them via cmd?
--Best regards
mohsen
8 years, 7 months
