>What does 'virsh list'
>give you onthe 2 hosts? Hopefully different names for
>the VMs ...
Yes, each host shows its own
# virsh list
Id Name Status
----------------------------------------------------
2 kvm101 running
# virsh list
Id Name State
----------------------------------------------------
1 kvm102 running
>Did you try 'fence_xvm -a {mcast-ip} -o list' on the
>guests as well?
fence_xvm sadly does not work on the Ubuntu guests. The howto said to
install "yum install fence-virt fence-virtd" which do not exist as such
in Ubuntu 18.04. After we tried to find the appropiate packages we
installed "libvirt-clients" and "multipath-tools". Is there maybe
something misisng or completely wrong?
Though we can connect to both hosts using "nc -z -v -u 192.168.1.21
1229", that just works fine.
>Usually, the biggest problem is the multicast traffic - as in many
>environments it can be dropped by firewalls.
To make sure I have requested our Datacenter techs to verify that
multicast Traffic can move unhindered in our local Network. But in the
past on multiple occasions they have confirmed, that local traffic is
not filtered in any way. But Since now I have never specifically asked
for multicast traffic, which I now did. I am waiting for an answer to
that question.
kind regards
Stefan Schmitz
Am 06.07.2020 um 11:24 schrieb Klaus Wenninger:
On 7/6/20 10:10 AM, stefan.schm...@farmpartner-tec.com wrote:
Hello,
# fence_xvm -o list
kvm102 bab3749c-15fc-40b7-8b6c-d4267b9f0eb9
on
This should show both VMs, so getting to that point will likely solve
your problem. fence_xvm relies on multicast, there could be some
obscure network configuration to get that working on the VMs.
You said you tried on both hosts. What does 'virsh list'
give you onthe 2 hosts? Hopefully different names for
the VMs ...
Did you try 'fence_xvm -a {mcast-ip} -o list' on the
guests as well?
Did you try pinging via the physical network that is
connected tothe bridge configured to be used for
fencing?
If I got it right fence_xvm should supportcollecting
answersfrom multiple hosts but I found a suggestion
to do a setup with 2 multicast-addresses & keys for
each host.
Which route did you go?
Klaus
Thank you for pointing me in that direction. We have tried to solve
that but with no success. We were using an howto provided here
https://wiki.clusterlabs.org/wiki/Guest_Fencing
Problem is, it specifically states that the tutorial does not yet
support the case where guests are running on multiple hosts. There are
some short hints what might be necessary to do, but working through
those sadly just did not work nor where there any clues which would
help us finding a solution ourselves. So now we are completely stuck
here.
Has someone the same configuration with Guest VMs on multiple hosts?
And how did you manage to get that to work? What do we need to do to
resolve this? Is there maybe even someone who would be willing to take
a closer look at our server? Any help would be greatly appreciated!
Kind regards
Stefan Schmitz
Am 03.07.2020 um 02:39 schrieb Ken Gaillot:
On Thu, 2020-07-02 at 17:18 +0200, stefan.schm...@farmpartner-tec.com
wrote:
Hello,
I hope someone can help with this problem. We are (still) trying to
get
Stonith to achieve a running active/active HA Cluster, but sadly to
no
avail.
There are 2 Centos Hosts. On each one there is a virtual Ubuntu VM.
The
Ubuntu VMs are the ones which should form the HA Cluster.
The current status is this:
# pcs status
Cluster name: pacemaker_cluster
WARNING: corosync and pacemaker node names do not match (IPs used in
setup?)
Stack: corosync
Current DC: server2ubuntu1 (version 1.1.18-2b07d5c5a9) - partition
with
quorum
Last updated: Thu Jul 2 17:03:53 2020
Last change: Thu Jul 2 14:33:14 2020 by root via cibadmin on
server4ubuntu1
2 nodes configured
13 resources configured
Online: [ server2ubuntu1 server4ubuntu1 ]
Full list of resources:
stonith_id_1 (stonith:external/libvirt): Stopped
Master/Slave Set: r0_pacemaker_Clone [r0_pacemaker]
Masters: [ server4ubuntu1 ]
Slaves: [ server2ubuntu1 ]
Master/Slave Set: WebDataClone [WebData]
Masters: [ server2ubuntu1 server4ubuntu1 ]
Clone Set: dlm-clone [dlm]
Started: [ server2ubuntu1 server4ubuntu1 ]
Clone Set: ClusterIP-clone [ClusterIP] (unique)
ClusterIP:0 (ocf::heartbeat:IPaddr2): Started
server2ubuntu1
ClusterIP:1 (ocf::heartbeat:IPaddr2): Started
server4ubuntu1
Clone Set: WebFS-clone [WebFS]
Started: [ server4ubuntu1 ]
Stopped: [ server2ubuntu1 ]
Clone Set: WebSite-clone [WebSite]
Started: [ server4ubuntu1 ]
Stopped: [ server2ubuntu1 ]
Failed Actions:
* stonith_id_1_start_0 on server2ubuntu1 'unknown error' (1):
call=201,
status=Error, exitreason='',
last-rc-change='Thu Jul 2 14:37:35 2020', queued=0ms,
exec=3403ms
* r0_pacemaker_monitor_60000 on server2ubuntu1 'master' (8):
call=203,
status=complete, exitreason='',
last-rc-change='Thu Jul 2 14:38:39 2020', queued=0ms, exec=0ms
* stonith_id_1_start_0 on server4ubuntu1 'unknown error' (1):
call=202,
status=Error, exitreason='',
last-rc-change='Thu Jul 2 14:37:39 2020', queued=0ms,
exec=3411ms
The stonith resoursce is stopped and does not seem to work.
On both hosts the command
# fence_xvm -o list
kvm102 bab3749c-15fc-40b7-8b6c-d4267b9f0eb9
on
This should show both VMs, so getting to that point will likely solve
your problem. fence_xvm relies on multicast, there could be some
obscure network configuration to get that working on the VMs.
returns the local VM. Apparently it connects through the
Virtualization
interface because it returns the VM name not the Hostname of the
client
VM. I do not know if this is how it is supposed to work?
Yes, fence_xvm knows only about the VM names.
To get pacemaker to be able to use it for fencing the cluster nodes,
you have to add a pcmk_host_map parameter to the fencing resource. It
looks like pcmk_host_map="nodename1:vmname1;nodename2:vmname2;..."
In the local network, every traffic is allowed. No firewall is
locally
active, just the connections leaving the local network are
firewalled.
Hence there are no coneection problems between the hosts and clients.
For example we can succesfully connect from the clients to the Hosts:
# nc -z -v -u 192.168.1.21 1229
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.1.21:1229.
Ncat: UDP packet sent successfully
Ncat: 1 bytes sent, 0 bytes received in 2.03 seconds.
# nc -z -v -u 192.168.1.13 1229
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.1.13:1229.
Ncat: UDP packet sent successfully
Ncat: 1 bytes sent, 0 bytes received in 2.03 seconds.
On the Ubuntu VMs we created and configured the the stonith resource
according to the howto provided here:
https://clusterlabs.org/pacemaker/doc/en-US/Pacemaker/1.1/pdf/Clusters_from_Scratch/Pacemaker-1.1-Clusters_from_Scratch-en-US.pdf
The actual line we used:
# pcs -f stonith_cfg stonith create stonith_id_1 external/libvirt
hostlist="Host4,host2"
hypervisor_uri="qemu+ssh://192.168.1.21/system"
But as you can see in in the pcs status output, stonith is stopped
and
exits with an unkown error.
Can somebody please advise on how to procced or what additionla
information is needed to solve this problem?
Any help would be greatly appreciated! Thank you in advance.
Kind regards
Stefan Schmitz
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