[libvirt-users] [virtual interface] detach interface during boot succeed with no changes
by Yalan Zhang
Hi guys,
when I detach an interface from vm during boot (vm boot not finished), it
always fail. I'm not sure if there is an existing bug. I have
confirmed with someone that for disk, there is similar behavior, if
this is also acceptable?
# virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh
detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh
dumpxml rhel7.2 |grep /interface -B9
Domain rhel7.2 destroyed
Domain rhel7.2 started
Interface detached successfully
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</controller>
<interface type='network'>
<mac address='52:54:00:98:c4:a0'/>
<source network='default' bridge='virbr0'/>
<target dev='vnet0'/>
<model type='rtl8139'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03'
function='0x0'/>
</interface>
When I detach after the vm boot, expand the sleep time to 10, it will succeed.
# virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh
detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh
dumpxml rhel7.2 |grep /interface -B9
Domain rhel7.2 destroyed
Domain rhel7.2 started
Interface detached successfully
-------
Best Regards,
Yalan Zhang
IRC: yalzhang
Internal phone: 8389413
1 year, 8 months
[libvirt-users] Question about disabling UFO on guest
by Bao Nguyen
Hello everyone,
I would like to ask a question regarding to disable UFO of virtio vNIC in
my guest. I have read the document at https://libvirt.org/formatdomain.html
*host*
The csum, gso, tso4, tso6, ecn and ufo attributes with possible
values on and off can be used to turn off host offloading options. By
default, the supported offloads are enabled by QEMU. *Since 1.2.9 (QEMU
only)* The mrg_rxbuf attribute can be used to control mergeable rx buffers
on the host side. Possible values are on (default) and off. *Since 1.2.13
(QEMU only)*
*guest*
The csum, tso4, tso6, ecn and ufo attributes with possible
values on and off can be used to turn off guest offloading options. By
default, the supported offloads are enabl
ed by QEMU.
*Since 1.2.9 (QEMU only)*
Then I disabled UFO on my vNIC on guest as the following configuration
<devices>
<interface type='network'>
<source network='default'/>
<target dev='vnet1'/>
<model type='virtio'/>
<driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off'
queues='5' rx_queue_size='256' tx_queue_size='256'>
*<host gso='off' ufo='off' />*
*<guest ufo='off'/>*
</driver>
</interface>
</devices>
Then I reboot my node to get the change effect and it works. However, can I
disable the UFO without touching the host OS? or it always has to disable
on both host and guest like that?
Thanks,
Brs,
Natsu
3 years, 9 months
[libvirt-users] ceph rbd pool and libvirt manageability (virt-install)
by Jelle de Jong
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Hello everybody,
I created a rbd pool and activated it, but I can't seem to create
volumes in it with virsh or virt-install?
# virsh pool-dumpxml myrbdpool
<pool type='rbd'>
<name>myrbdpool</name>
<uuid>2d786f7a-2df3-4d79-ae60-1535bcf1c6b5</uuid>
<capacity unit='bytes'>6997998301184</capacity>
<allocation unit='bytes'>10309227031</allocation>
<available unit='bytes'>6977204658176</available>
<source>
<host name='ceph01.powercraft.nl' port='6789'/>
<host name='ceph02.powercraft.nl' port='6789'/>
<host name='ceph03.powercraft.nl' port='6789'/>
<name>libvirt-pool</name>
<auth type='ceph' username='libvirt'>
<secret uuid='029a334e-ed57-4293-bb99-ffafa8867122'/>
</auth>
</source>
</pool>
# virt-install --version
1.0.1
# virsh --version
1.2.9
I ended using virsh edit ceph-test.powercraft.nl and making creating
the disk manually.
<disk type='network' device='disk'>
<auth username='libvirt'>
<secret type='ceph' uuid='029a334e-ed57-4293-bb99-ffafa8867122'/>
</auth>
<source protocol='rbd' name='libvirt-pool/kvm01-storage'>
<host name='ceph01.powercraft.nl' port='6789'/>
<host name='ceph02.powercraft.nl' port='6789'/>
<host name='ceph03.powercraft.nl' port='6789'/>
</source>
<target dev='vdc' bus='virtio'/>
</disk>
I use virt-install a lot to define, import and undefine domains, how
can I use virt-install to manage my rdb disks?
Kind regards,
Jelle de Jong
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5 years, 8 months
[libvirt-users] virRandomBits - not very random
by Brian Rak
I just ran into an issue where I had about 30 guests get duplicate mac
addresses assigned. These were scattered across 30 different machines.
Some debugging revealed that:
1) All the host machines were restarted within a couple seconds of each
other
2) All the host machines had fairly similar libvirtd pids (within ~100
PIDs of each other)
3) Libvirt seeds the RNG using 'time(NULL) ^ getpid()'
This perfectly explains why I saw so many duplicate mac addresses.
Why is the RNG seed such a predictable value? Surely there has to be a
better source of a random seed then the timestamp and the pid?
The PID seems to me to be a very bad source of any randomness. I just
ran a test across 60 of our hosts. 43 of them shared their PID with at
least one other machine.
5 years, 11 months
[libvirt-users] Create qcow2 v3 volumes via libvirt
by Gionatan Danti
Hi all,
on a fully patched CentOS 7.4 x86-64, I see the following behavior:
- when creating a new volumes using vol-create-as, the resulting file is
a qcow2 version 2 (compat=0.10) file. Example:
[root@gdanti-lenovo vmimages]# virsh vol-create-as default zzz.qcow2
8589934592 --format=qcow2 --backing-vol /mnt/vmimages/centos6.img
Vol zzz.qcow2 created
[root@gdanti-lenovo vmimages]# file zzz.qcow2
zzz.qcow2: QEMU QCOW Image (v2), has backing file (path
/mnt/vmimages/centos6.img), 8589934592 bytes
[root@gdanti-lenovo vmimages]# qemu-img info zzz.qcow2
image: zzz.qcow2
file format: qcow2
virtual size: 8.0G (8589934592 bytes)
disk size: 196K
cluster_size: 65536
backing file: /mnt/vmimages/centos6.img
backing file format: raw
Format specific information:
compat: 0.10
refcount bits: 16
- when creating a snapshot, the resulting file is a qcow2 version 3
(comapt=1.1) file. Example:
[root@gdanti-lenovo vmimages]# virsh snapshot-create-as centos6left
--disk-only --no-metadata snap.qcow2
Domain snapshot snap.qcow2 created
[root@gdanti-lenovo vmimages]# file centos6left.snap.qcow2
centos6left.snap.qcow2: QEMU QCOW Image (v3), has backing file (path
/mnt/vmimages/centos6left.qcow2), 8589934592 bytes
[root@gdanti-lenovo vmimages]# qemu-img info centos6left.snap.qcow2
image: centos6left.snap.qcow2
file format: qcow2
virtual size: 8.0G (8589934592 bytes)
disk size: 196K
cluster_size: 65536
backing file: /mnt/vmimages/centos6left.qcow2
backing file format: qcow2
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false
From what I know, this is a deliberate decision: compat=1.1 requires
relatively recent qemu version, and creating a new volume play on the
"safe side" of compatibility.
It is possible to create a new volume using qcow2 version 3 (compat=1.1)
format *using libvirt/virsh* (I know I can do that via qemu-img)? Any
drawback on using version 3 format?
Thanks.
--
Danti Gionatan
Supporto Tecnico
Assyoma S.r.l. - www.assyoma.it
email: g.danti(a)assyoma.it - info(a)assyoma.it
GPG public key ID: FF5F32A8
5 years, 12 months
[libvirt-users] Unable to detach disk using 'virsh detach-disk'
by Andre Goree
I'm unable to detach a disk from a Windows guest using the 'virsh
detach-disk' command.
Even though 'domblklist' shows the disk attached, and on the FIRST
iteration, it says the command "completed successfully," 'domblklist
will still show the disk attached and subsequent 'detach-disk' commands
fail with 'no disk found whose source path or target is ${location}'
~ # virsh domblklist 31907-1063435
Target Source
------------------------------------------------
vda ${concatenated}/31907-1063435/2018-04-28-190529
vdb
${concatenated}/31907-67863/2018-03-21-033216.2018-04-28-190529
~ # virsh detach-disk --domain 31907-1063435
/var/lib/libvirt/images/instances/31907-67863/2018-03-21-033216.2018-04-28-190529
--persistent
error: No disk found whose source path or target is
/var/lib/libvirt/images/instances/31907-67863/2018-03-21-033216.2018-04-28-190529
Any ideas as to why this happens?
--
Andre Goree
-=-=-=-=-=-
Email - andre at drenet.net
Website - http://blog.drenet.net
PGP key - http://www.drenet.net/pubkey.html
-=-=-=-=-=-
6 years
[libvirt-users] User name / session idin logs
by Anastasiya Ruzhanskaya
Hello everyone,
I have a question about logging. I need to find out whether it is possible
to see user id/session id inside logs or somewhere else. It is not passed
in structured across the network, so where should I look to find out, which
user (which session) is currently performing the actions?
6 years
[libvirt-users] connecting host and guest vm using a dummy nic
by daggs
Greetings all,
I have a host machine that runs a router within a vm.
I want to allow a connection between the host and the guest so the host can connect to the lan provided by the router vm.
I've created a dummy interface with these commands:
$ ip link add ens99-dummy type dummy
$ ip link set ens99-dummy address 52:54:00:1f:d0:ff
this resulted with this output:
$ ifconfig ens99-dummy
ens99-dummy Link encap:Ethernet HWaddr 52:54:00:1F:D0:FF
inet6 addr: fe80::84b5:24ff:fe62:c16d/64 Scope:Link
UP BROADCAST RUNNING NOARP MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:899 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:321727 (314.1 KiB)
in my libvirt's xml file I have this entry:
<interface type='direct'>
<mac address='52:54:00:0c:cb:3e'/>
<source dev='ens99-dummy' mode='private'/>
<target dev='macvtap0'/>
<model type='e1000'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x02' slot='0x01' function='0x0'/>
</interface>
after the vm is up, I see the adapter in the vm and the host has one more entry:
$ ifconfig macvtap0
macvtap0 Link encap:Ethernet HWaddr 52:54:00:0C:CB:3E
inet6 addr: fe80::5054:ff:fe0c:cb3e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:889 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:0 (0.0 B) TX bytes:320523 (313.0 KiB)
but when I try to request ip via dhcp from both macvtap0 and ens99-dummy I don't get any.
any idea why?
6 years
