How to Set Up Real-Time NFS Backup with Inotify and Rsync on Linux

Task Requirements

1. Real‑time backup of static resources on an NFS server using inotify + rsync.

Host List

# External IP   Internal IP   Hostname
192.168.122.207 172.16.1.207 web-test-209
192.168.122.231 172.16.1.231 nfs-test-231
192.168.122.241 172.16.1.241 rsync-test-241

Architecture Diagram

1. Set up rsync on rsync-test-241

1.1 Install rsync

# yum install rsync -y

1.2 Modify configuration file /etc/rsyncd.conf

uid = rsync
gid = rsync
fake super = yes
use chroot = no
max connections = 200
pid file = /var/run/rsyncd.pid
lock file = /var/run/rsync.lock
log file = /var/log/rsyncd.log
ignore errors
read only = false
list = false
hosts allow = 172.16.1.0/24
hosts deny = 0.0.0.0/32
auth users = rsync_backup
secrets file = /etc/rsync.password

[backup-nfs]
comment = This is nfs backup!
path = /backup/

uid / gid : run rsync daemon as the rsync user.

use chroot = no : disable chroot for internal network sync.

max connections = 200 : maximum concurrent connections.

read only = false : allow read‑write access.

hosts allow / deny : whitelist and blacklist IP ranges.

auth users : virtual user for authentication.

secrets file : password file for the virtual user.

path : directory to be backed up.

1.3 Create user, directory and authentication file

# useradd rsync -s /sbin/nologin -M
# id rsync
# mkdir /backup
# chown -R rsync.rsync /backup/
# echo "rsync_backup:mima666" > /etc/rsync.password
# chmod 600 /etc/rsync.password

1.4 Start rsync service and enable at boot

# systemctl start rsyncd
# systemctl enable rsyncd

1.5 Verify rsync service

# systemctl status rsyncd
# ps -ef|grep rsync
# netstat -tnlp | grep rsync

2. Install rsync on nfs-test-231

2.1 Install rsync

# yum install rsync -y

2.2 Create password file

# echo 'mima666' > /etc/rsync.password
# chmod 600 /etc/rsync.password

2.3 Test rsync data sync

# rsync -avzP network_init.sh [email protected]::backup-nfs --password-file=/etc/rsync.password

Flags: -a preserve attributes, -v verbose, -z compress, -P show progress.

3. Deploy inotify on nfs-test-231

3.1 Install inotify‑tools

# yum install inotify-tools -y

3.2 Write script rsync_nginx.sh

#!/bin/bash
/usr/bin/inotifywait -mrq -e modify,delete,create,attrib,move /nfs-web-share/ | while read line
do
    rsync -a --delete /nfs-web-share/ [email protected]::backup-nfs --password-file=/etc/rsync.password
    echo "`date +%F\ %T`出现事件$line" >> /var/log/rsync.log 2>&1
done

3.3 Run script in background

# bash rsync_nginx.sh &

4. Verify synchronization

4.1 Update file on web-test-207

# cd /usr/share/nginx/html/
# vim index.html
# cat index.html

4.2 Check log on nfs-test-231

# tail -f /var/log/rsync.log

4.3 Check backup on rsync-test-241

# cd /backup/
# ls
# cat index.html

If the process fails, common reasons include firewall blocks, incorrect NFS permissions, or network connectivity issues; consult error messages for further troubleshooting.