Originally Posted by lizmatt

I think you can use rsync and get the content copied from Server1 to Server 2 at regular interval.

Not just at regular intervals, it will synchronise continuously. But not instantaneously! There will always be a delay. See https://linux.die.net/man/1/rsync for documentation.

BE CAREFUL if you try this. You can easily bring down a server if you don’t know what you’re doing. Or two servers.

If you try to synchronise a large file that changes frequently such as a log file, it’s likely that it will never catch up and it may eat all your cpu, all your memory and all your network bandwidth as it tries. You will need to carefully exclude cache files, temp files and some system files as well.

You will also need to be careful with file ownership and permissions. You can easily synchronise to the wrong user and make files unreadable or unwriteable.

Timestamps might change and cause problems as well.

You won’t be able to synchronise database contents this way, that requires a different solution.

If you’re trying to create a “hot failover” machine you may run into problems with deciding when to switch and when to switch back. It’s easy to get that wrong.

If the servers get out of sync even for a very short time, you may lose money if the servers are used for eCommerce or email hosting.

If one of the servers is hacked, or (more likely) a bunch of files are deleted accidentally, the problem will propagate to the synchronised machine and you may make reliability WORSE.

If you google “high availability tutorial” you will find lots of information about setting all this up.