How to Set Up Real‑Time NFS Backup with inotify and rsync

Task Requirements

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

Implementation Steps

1. Set up rsync on rsync-test-241

1.1 Install rsync

[root@rsync-test-241 ~]# yum install rsync -y

1.2 Edit /etc/rsyncd.conf

# vim /etc/rsyncd.conf
# cat /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/

Key configuration parameters:

Parameter

Description

uid = rsync

Run rsync daemon as user

rsync

gid = rsync

Run rsync daemon as group

rsync

use chroot = no

Disable chroot for internal network sync

max connections = 200

Maximum concurrent connections

timeout = 300

Close idle connections after 300 seconds

pid file = /var/run/rsyncd.pid

File storing daemon PID

lock file = /var/run/rsync.lock

Lock file for connection limiting

log file = /var/log/rsyncd.log

Log file location

[backup-nfs] / path = /backup/

Backup module and directory

read only = false

Allow write access

hosts allow = 172.16.1.0/24

Whitelist of allowed client networks

hosts deny = 0.0.0.0/32

Blacklist (default deny)

auth users = rsync_backup

Virtual user for authentication

secrets file = /etc/rsync.password

Password file for the virtual user

1.3 Create rsync user, directory and password file

# useradd rsync -s /sbin/nologin -M
# id rsync
uid=1000(rsync) gid=1000(rsync) groups=1000(rsync)

# mkdir /backup
# chown -R rsync.rsync /backup/
# ls -ld /backup/
drwxr-xr-x 2 rsync rsync ... /backup/

# echo "rsync_backup:mima666" > /etc/rsync.password
# chmod 600 /etc/rsync.password

1.4 Enable and start rsync daemon

# systemctl start rsyncd
# systemctl enable rsyncd

1.5 Verify rsync service

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

2. Install and run 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 synchronization

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

Options:

-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 monitoring script

#!/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) event $line" >> /var/log/rsync.log 2>&1
done

3.3 Run script in background

# bash rsync_nginx.sh &

4. Verify synchronization

4.1 Modify a file on web-test-207

# cd /usr/share/nginx/html/
# vim 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 causes are firewall rules, NFS permission settings, or network connectivity problems.