1. Environment
- Operating system: CentOS 7
Host:
- master 192.168.0.98
- backup 192.168.0.166
Goal: Incrementally copy from online to online at 3 am every day .master/wwwbackup
2. Configure the password-free login of the host
Configure the secret-free login of the host on Backup, please refer to SSH public key secret-free login[1]
3. Rsync service
Install Rsync on both master and slave
yum install -y rsync
Note that the following steps only need to be configured on the slave backup, not the master.
Create a file synchronization service on the slave Backup
vi /lib/systemd/system/filesync.service
Fill in the following content, pay attention to modify the host IP part of the source address of rsync synchronization
[Unit]
Description=rsync file sync service.
[Service]
User=root
Type=oneshot
ExecStart=/usr/bin/bash -c 'rsync -av --delete [email protected]:/www/ /www'
[Install]
WantedBy=multi-user.target
[email protected]Please replace the part with the specific Master host address and user.--deleteIndicates synchronous deletion, see rsync usage tutorial [2] for details
Note that please complete the configuration of the slave backup to log in to the master without password first, otherwise the service will be invalid.
reload service
systemctl daemon-reload
The above service implements: incremental replication from masterup to up./wwwbackup
4. Timer
Note that this step only needs to be configured on the slave backup, not the master.
In order to achieve: every day at 3 am, a timer needs to be created.
The timer service of Systemd is used here
Create the following file, the file name can be customized, and the suffix is fixed as.timer
vi /lib/systemd/system/filesync.timer
Fill in the following content
[Unit]
Description=filesync.service timer.
[Timer]
Unit=filesync.service
OnCalendar=*-*-* 03:00:00
[Install]
WantedBy=multi-user.target
[Timer]The value inUnitneeds to be the same as the name of the service file created in the previous step.OnCalendarFor parameter configuration, please refer to freedesktop. systemd.timer.html
reload service
systemctl daemon-reload
Set the timer to start automatically
systemctl enable filesync.timer
start timer
systemctl start filesync.timer
View the currently running timer and check whether the timer is valid
systemctl list-timers
5. Check the file synchronization log
When the timer expires filesync.service, the service will be automatically started. After the service is running, you can view the file synchronization information through the following command:
journalctl -f -u filesync.service
references
[1]. csdn. SSH public key password-free login. cliven. 2022.10.13. https://blog.csdn.net/q1009020096/article/details/125166499
[2]. Ruan Yifeng Blog. rsync usage tutorial. Ruan Yifeng . 2020.8.26. https://www.ruanyifeng.com/blog/2020/08/rsync.html
[3]. Ruan Yifeng Blog. Systemd Timer Tutorial. Ruan Yifeng. 2018.3.30 . https://www. ruanyifeng.com/blog/2018/03/systemd-timer.html
[4]. freedesktop. systemd.timer. https://www.freedesktop.org/software/systemd/man/systemd.timer.html#