Nagios Support Forum

Hello.

I need advice/sugestion about migration everything from one server to another.
Old server is on CentOS 6 with Nagios XI 5.7.4 and new server will be on CentOS 7 with same version of Nagios XI.
I already build several times in test environment new server and I think it takes some 1,5h to built new server, or more.
New server should get IP configuration of old server.

I need advice on migrating the old server to the new server. I have already built an new server in a test environment and I think it takes at least an hour and a half to install and configure everything. The new server should have the same configuration as the old server, meaning the same IP address. Well, if it takes at 1,5 hour and a half, or maybe two hours to configure a new server, which is your advice that when the old server is unavailable (because the IP address will be taken from the old server by the new server), monitoring will still be available to colleagues and everyone who monitors the state of the system?
Is it possible for the old server to stay with the old IP configuration and for the new server to be installed with a different IP address and at the time of replacing the server, the old server is shut down and the new server is configured with a new IP address?


BR,
BIB.

HI BIB,

Looks like you are making good progress on the migration. With Nagios XI, your license allows for three separate activations: production, test, and backup. You can safely set up the new system on another IP and make the change over whenever you are ready.

See: Nagios XI License Entitlements

Let us know if you have further questions.

--Benjamin

Hello Benjamin.

Thank you for advice.
I understood about licenses. The problem is that the production server is at one IP address and in order for the replacement server to be installed, of course it must be at another IP address. So my question is, can a replacement server be installed and completely configured with a different IP address and then at one point shut down the production server and the replacement server simply retrieve the IP address from the production server? Is there anything else to change in the nagios system besides a simple network configuration?

Waiting for your advice.

BR,
BIB.

Hi,

That's correct, that will work. Besides the network settings, you just need to update the Program URL in Nagios XI.....Admin > System Config > Manage System Config > General Program Settings

More details on this article: Configuring Your Server With A Static IP Address

Let us know if you have any other questions.

--Benjamin

Hello Benjamin.

If that program url is DNS data then it needs to change only IP configuration, because if old, production server use nagios-bgd DNS name and new server should use the same DNS name and nothing changes.

Few questions.
if we install a new server with a new IP setting and hostname, at the time of replacing the new one instead of the old one, is it necessary to replace the hostname in the nagios system somewhere else in order for the new server to take over the production IP address and hostname or just reconfigure network configuration?

Our backup file is ~7GB. Is there any possibility to reduce the size of the backup file itself and to delete unnecessary items?

At the time of replacing the old server with a new one, the new server will have less information regarding the server's performance. Is there a possibility to somehow merge all the data on the new server?

Thank you.

Hi,

Regarding the network questions, I would recommend reaching out to your admin as well to minimize any downtime. If you are using DNS, and the new server will have the same hostname, then you'll need to configure the new server with a new static IP address, and then update your DNS server to configure the domain name to the new address.

By default, I would recommend taking a look at the following guide and adjusting the database retention levels down. This will help boost performance and remove any historical data that's not needed and help reduce the size of the back archive.

Nagios XI Database Optimization

That said, the backup archive contains everything and can be large so you won't lose any data when running the restore.

Let us know if you have more questions.

--Benjamin

Hello Benjamin.

Thank you for replying. I was waiting for you to appear on the forum.
I understand all what you advised. I will take a look to optimizing database.
We will use the same hostname like is on production server (because our DNS server configured with do not update DNS records) and with different IP address, so it will be very easy later just to reconfigure network configuration.

One more question what is important.
At the time of replacing the old server, it is necessary to backup the configuration on the old server and while the old server is still in production, do a restore on the new server and install the necessary plugins and only then replace the old server with a new one. The question for this, since there is a moment of time from which the configuration and performance logs were backed up to the moment of starting the new server, is there a possibility that somehow the data from the old server and the data from the new server are merged so that not is there that hole in a time where there is no performance data? Or maybe just backup performance logs and restore them on new server?

Thank you.
BE.
BIB.

Hi BIB,

Since it's not a high availability setup, there is going to be some lag between running the backup on the production systems and restoring this on the new server.

However, in order to minimize this, I would disable the notifications on the test server globally, run the restore and make sure all the plugins are working correctly and returning expected data. Some may require extra dependencies not included in the default installations.

Once everything this running smoothly you can re-run the backup/restore process again, configure DNS, and then enable notifications from the new system.

Hope that helps answer your question.

Regards,
Benjamin

Hello Benjamin again.

Thanks for the explanation. I would ask for further explanation. If I understood your explanation well, after the initial restore of everything from the production server and after the installation and configuration of all plugins/agents, is it possible to restore the latest backup from the production server again? Here we have to keep in mind that there is no plugin for VMWare on the old, production server and some plugins on the new server are newer versions. Will it restore the latest backup, run over some files (configuration files maybe) that are more recent than the old server?
In one post I was looking for an option to discard something that was done wrong and I was advised by Nagios support that there is no option for something like that but a backup must be done and restored if something is configured incorrectly. That is clear, ie. yes restore backup can be done but here is the issue of restore backup from server where there is a slightly older OS and the same version of Nagios XI so I think the issue is in place so I would like to clarify that we have no possible problems.

Is it possible that the entire folder with perfomance data can be manually backed up and extracted on a new server? Restart some service maybe then?

I understood about HA but we don't need to have high availability right now.

BR,
BIB

Hi Bib,

I looked into this further and you can copy over the perfdata from the old system to the new, so it's not necessary to do a full restore.

However, please find out if the older system is 32-bit architecture. For those systems, there are a few more steps involved and we have a KB article on how to do this.

Nagios XI - Migrate Performance Data

Let me know.

Thanks,
Benjamin