enable rsync to run permanently - linux

Question

I have two machines, both running on linux with centos 7.
I have installed the rsync packages on both of them and i am able to sync a directory from one machine to the other.
Right now i am doing the syncing manually, each time i want to sync i am running the next line:
rsync -r /home/stuff root#123.0.0.99/home
I was wondering if there is a way of configuring the rsync to do the syncing automatically, every some amount of time or preferably when there is a new file of sub directory in the home directory?
Thank you for your help.
Any help would be appreciated.

Answer 1

If you want to rsync every some amount of time you can use cronjobs which can be configured to run a specific command each amount of time and if you want to run rsync when there is an update or modification you can use lsyncd. check this article about use lsyncd
Update:
As links might get outdated, I will add this brief example (You are free to modify it with what works best for you):
First create an ssh key on the source machine and then add the public key at the ~/.ssh/authorized_keys file on the destination machine.
In the source machine update this file ~/.ssh/config with the following content:
# ~/.ssh/config
...
Host my.remote.server
identityfile ~/.ssh/id_rsa
IdentitiesOnly yes
hostname 123.0.0.99
user root
port 22
...
And configure your lsyncd with the following then restart lsyncd's service
# lsyncd.conf
...
sync {
default.rsyncssh,
source="/home/stuff",
host="my.remote.server",
targetdir="/home/stuff",
excludeFrom="/etc/lsyncd/lsyncd.exclude",
rsync = {
archive = true,
}
}
...

Answer 2

You can setup an hourly cron job to do this.
rsync in itself is quite efficient in that it only transfers changes.
You can find more info about cron here: cron