This is resolved, and my environment is 100% stable now.

Or was, until I then used the engine to "upgrade" one of the hosts, at which point I started having problems again after the reboot, because the old vlan came back.

I'll finish getting things stabilized today, and hopefully won't run into this again.

I've been turning things on and off quite a bit, because they aren't in a proper data center (yet) and are just sitting here in my home office.

So I'm sure shutting them down and turning them back on fairly often hasn't helped the situation.

I initially had a few issues going on:

I of course first broke things when I tried to change the management vlan
Aside from my notes below and the troubleshooting steps I went through, yesterday, I had forgotten that connectivity to the DNS server hadn't been restored. Once I got DNS operational, the engine was able to see two of the hosts, and finally started showing some green.
I then went in and ran `hosted-engine --vm-stop` to shutdown the engine, and then I started it again... and viola. The last remaining problematic host came online, and a few minutes later, the disks, volumes, and datacenter came online.
I think part of my problem has been this switch. I purchased a Netgear GS324T for my frontend traffic. But I've also needed to put my backend traffic onto some temporary ports on that switch until I can get a VM controller setup that will run my other switch, a Ubiquiti US-XG-16 for my permanent backend traffic. The Netgear hasn't been nearly as simple to configure as I had hoped. The vlan behavior has also been inconsistent - sometimes I have vlan settings in place, and things work. Sometimes they don't work. It has also been re-assigning a of the vlans occasionally after reboots, which has been frustrating. I'm close to being completely done configuring the infrastructure, but I'm also getting increasingly tempted to go find a different switch.

Lessons learned:

Always make sure DNS is functional

I was really hoping that I could run DNS as a VM (or multiple VMs) inside the cluster.
That said, if the cluster and the engine won't even start correctly without, then I may need to run DNS externally. I'm open to feedback on this.

I have 1 extra U of space at the datacenter reserved, and I do have a 4th spare server that I haven't decided what to do with yet. It has way more CPU and RAM than would be necessary to run an internal DNS server... but perhaps I have no choice. Thoughts?

Make sure your vlan settings are correct before you start deploying the hosted engine and configure oVirt.
If possible, don't turn off and turn on your servers constantly. :) I realize this is a given. I just don't have much choice in the matter right now, due to lack of datacenter in my home office.

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Friday, April 9, 2021 5:55 AM, David White via Users <users@ovirt.org> wrote:

I was able to fix the connectivity issues between all 3 hosts.

It turned out that I hadn't completely deleted the old vlan settings from the host. I re-ran "nmcli connection delete" on the old vlan. After that, I had to edit a network-scripts file and change/fix the bridge to use ifcfg-ovirtmgmt.

After I did all that, the problematic host was accessible again. All 3 Gluster peers are now able to see each other and communicate over the management network.

From the command line, I was then able to successfully run "hosted-engine --connect-storage" without errors. I was also able to then run "hosted-engine --vm-start".

Unfortunately, the engine itself is still unstable, and when I access the web UI / oVirt Manager, it shows that all 3 hosts are inaccessible and down.

I don't understand how the web UI is operational at all if the engine thinks that all 3 hosts are inaccessible. What's going on there?

Although the initial problem was my own doing (I changed the management vlan), I'm deeply concerned with how unstable everything became - and has continued to be- ever since I lost connectivity to the 1 host. I thought the point of all of this was that things would (should) continue to work if 1 of the hosts went away.

Anyway, at that point, all 3 hosts are able to communicate with each other over the management network, but the engine still thinks that all 3 hosts are down, and is unable to manage anything.

Any suggestions on how to proceed would be much appreciated.

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Wednesday, April 7, 2021 8:28 PM, David White <dmwhite823@protonmail.com> wrote:

I still haven't been able to resurrect the 1st host, so I've spent some time trying to get the hosted engine stable. I would welcome input on how to fix the problematic host so that it can be accessible again.

As per my original email, this all started when I tried to change the management vlan. I honestly cannot remember what I did (if anything) to the actual hosts when this all started, but my troubleshooting steps today have been to try to fiddle with the vlan settings and /etc/sysconfig/network-scripts/ files on the problematic host to switch from the original vlan (1) to the new vlan (10).

Until then, I'm troubleshooting why the hosted engine isn't really working, since the other two hosts are operational.

The hosted engine is "running" -- I can access and navigate around the oVirt Manager.

However, it appears that all of the storage domains are down, and all of the hosts are "NonOperational". I was, however, able to put two of the hosts into Maintenance Mode, including the problematic 1st host.

This is what I see on the 2nd host:

[root@cha2-storage network-scripts]# gluster peer status

Hostname: cha1-storage.mgt.example.com

Uuid: 348de1f3-5efe-4e0c-b58e-9cf48071e8e1

State: Peer in Cluster (Disconnected)

Hostname: cha3-storage.mgt.example.com

Uuid: 0563c3e8-237d-4409-a09a-ec51719b0da6

State: Peer in Cluster (Connected)

[root@cha2-storage network-scripts]# hosted-engine --vm-status

The hosted engine configuration has not been retrieved from shared storage. Please ensure that ovirt-ha-agent is running and the storage server is reachable.

[root@cha2-storage network-scripts]# hosted-engine --connect-storage

Traceback (most recent call last):

File "/usr/lib64/python3.6/runpy.py", line 193, in _run_module_as_main

"__main__", mod_spec)

File "/usr/lib64/python3.6/runpy.py", line 85, in _run_code

exec(code, run_globals)

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_setup/connect_storage_server.py", line 30, in <module>

timeout=ohostedcons.Const.STORAGE_SERVER_TIMEOUT,

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/client/client.py", line 312, in connect_storage_server

sserver.connect_storage_server(timeout=timeout)

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/lib/storage_server.py", line 394, in connect_storage_server

'Connection to storage server failed'

RuntimeError: Connection to storage server failed

The ovirt-engine-ha service seems to be continuously trying to load / activate, but failing:

[root@cha2-storage network-scripts]# systemctl status -l ovirt-ha-agent

● ovirt-ha-agent.service - oVirt Hosted Engine High Availability Monitoring Agent

Loaded: loaded (/usr/lib/systemd/system/ovirt-ha-agent.service; enabled; vendor preset: disabled)

Active: activating (auto-restart) (Result: exit-code) since Wed 2021-04-07 20:24:46 EDT; 60ms ago

Process: 124306 ExecStart=/usr/share/ovirt-hosted-engine-ha/ovirt-ha-agent (code=exited, status=157)

Main PID: 124306 (code=exited, status=157)

Some recent entries in /var/log/ovirt-hosted-engine-ha/agent.log

MainThread::ERROR::2021-04-07 20:22:59,115::agent::144::ovirt_hosted_engine_ha.agent.agent.Agent::(_run_agent) Trying to restart agent

MainThread::INFO::2021-04-07 20:22:59,115::agent::89::ovirt_hosted_engine_ha.agent.agent.Agent::(run) Agent shutting down

MainThread::INFO::2021-04-07 20:23:09,717::agent::67::ovirt_hosted_engine_ha.agent.agent.Agent::(run) ovirt-hosted-engine-ha agent 2.4.6 started

MainThread::INFO::2021-04-07 20:23:09,742::hosted_engine::242::ovirt_hosted_engine_ha.agent.hosted_engine.HostedEngine::(_get_hostname) Certificate common name not found, using hostname to identify host

MainThread::INFO::2021-04-07 20:23:09,837::hosted_engine::548::ovirt_hosted_engine_ha.agent.hosted_engine.HostedEngine::(_initialize_broker) Initializing ha-broker connection

MainThread::INFO::2021-04-07 20:23:09,838::brokerlink::82::ovirt_hosted_engine_ha.lib.brokerlink.BrokerLink::(start_monitor) Starting monitor network, options {'addr': '10.1.0.1', 'network_test': 'dns', 'tcp_t_address': '', 'tcp_t_port': ''}

MainThread::ERROR::2021-04-07 20:23:09,839::hosted_engine::564::ovirt_hosted_engine_ha.agent.hosted_engine.HostedEngine::(_initialize_broker) Failed to start necessary monitors

MainThread::ERROR::2021-04-07 20:23:09,842::agent::143::ovirt_hosted_engine_ha.agent.agent.Agent::(_run_agent) Traceback (most recent call last):

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/lib/brokerlink.py", line 85, in start_monitor

response = self._proxy.start_monitor(type, options)

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1112, in __call__

return self.__send(self.__name, args)

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1452, in __request

verbose=self.__verbose

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1154, in request

return self.single_request(host, handler, request_body, verbose)

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1166, in single_request

http_conn = self.send_request(host, handler, request_body, verbose)

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1279, in send_request

self.send_content(connection, request_body)

File "/usr/lib64/python3.6/xmlrpc/client.py", line 1309, in send_content

connection.endheaders(request_body)

File "/usr/lib64/python3.6/http/client.py", line 1249, in endheaders

self._send_output(message_body, encode_chunked=encode_chunked)

File "/usr/lib64/python3.6/http/client.py", line 1036, in _send_output

File "/usr/lib64/python3.6/http/client.py", line 974, in send

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/lib/unixrpc.py", line 74, in connect

self.sock.connect(base64.b16decode(self.host))

FileNotFoundError: [Errno 2] No such file or directory

During handling of the above exception, another exception occurred:

Traceback (most recent call last):

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/agent/agent.py", line 131, in _run_agent

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/agent/agent.py", line 55, in action_proper

return he.start_monitoring()

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", line 437, in start_monitoring

self._initialize_broker()

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", line 561, in _initialize_broker

m.get('options', {}))

File "/usr/lib/python3.6/site-packages/ovirt_hosted_engine_ha/lib/brokerlink.py", line 91, in start_monitor

).format(t=type, o=options, e=e)

ovirt_hosted_engine_ha.lib.exceptions.RequestError: brokerlink - failed to start monitor via ovirt-ha-broker: [Errno 2] No such file or directory, [monitor: 'network', options: {'addr': '10.1.0.1', 'network_test': 'dns', 'tcp_t_address': '', 'tcp_t_port': ''}]

MainThread::ERROR::2021-04-07 20:23:09,842::agent::144::ovirt_hosted_engine_ha.agent.agent.Agent::(_run_agent) Trying to restart agent

MainThread::INFO::2021-04-07 20:23:09,842::agent::89::ovirt_hosted_engine_ha.agent.agent.Agent::(run) Agent shutting down

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Wednesday, April 7, 2021 5:36 PM, David White via Users <users@ovirt.org> wrote:

I'm working on setting up my environment prior to production, and have run into an issue.

I got most things configured, but due to a limitation on one of my switches, I decided to change the management vlan that the hosts communicate on. Over the course of changing that vlan, I wound up resetting my router to default settings.

I have the router operational again, and I also have 1 of my switches operational.

Now, I'm trying to bring the oVirt cluster back online.

This is oVirt 4.5 running on RHEL 8.3.

The old vlan is 1, and the new vlan is 10.

Currently, hosts 2 & 3 are accessible over the new vlan, and can ping each other.

I'm able to ssh to both hosts, and when I run "gluster peer status", I see that they are connected to each other.

However, host 1 is not accessible from anything. I can't ping it, and it cannot get out.

As part of my troubleshooting, I've done the following:

From the host console, I ran `nmcli connection delete` to delete the old vlan (VLAN 1).

I moved the /etc/sysconfig/network-scripts/interface.1 file to interface.10, and edited the file accordingly to make sure the vlan and device settings are set to 10 instead of 1, and I rebooted the host.

The engine seems to be running, but I don't understand why.

From each of the hosts that are working (host 2 and host 3), I ran "hosted-engine --check-liveliness" and both hosts indicate that the engine is NOT running.

Yet the engine loads in a web browser, and I'm able to log into /ovirt-engine/webadmin/.

The engine thinks that all 3 hosts is nonresponsive. See screenshot below:

What I'm really looking for help with is to get the first host back online.

Once it is healthy and gluster is healthy, I feel confident I can get the engine operational again.

What else should I look for on this host?