How to Install and Configure LsyncD on AlmaLinux
LsyncD (Live Syncing Daemon) is used to sync or replicate both files and directories locally and remotely after a specific interval of time. LsyncD uses rsync and ssh in the backend.
LsyncD works on Master and Slave architecture. It will monitor the directory on the master server. If any changes or modifications occur on the Master server, LsyncD will replicate them on its slave servers after a specific interval of time. These frequent directory updates and synchronization actions ensure that the master and slave directories remain identical.
In this article, we will discuss how to install and configure LsyncD on AlmaLinux servers.
Requirements
- Master server and Slave server.
- Operating system and version: AlmaLinux OS 8.5.
- Processor: 1.1 GHz.
- RAM: Minimum 1 GB but recommended 2 GB.
- Disk Space: Minimum 20 GB but recommended 40 GB.
- Architecture: 64-bit.
- Software: LsyncD and SSHD.
- Root access to your Linux system or via the sudo command.
How to Install and Configure LsyncD on AlmaLinux
To proceed with the installation and configuration, you need two servers that have AlmaLinux installed - one server for Master Server (IP: 192.168.1.20 in this example) and one server for Slave Server (IP: 192.168.1.21 in this example).
Step 1: Enable Key-based Authentication Between Master and Slave Server.
From the Master server, generate the public and private keys using the ssh-keygen command.
Here is the output.
[root@noufserver-master ~]# ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:IU8Zc98zsgAVIlSCgchSavTv+kkUyC53LWo/LAOPV6c root@noufserver-master
The key's randomart image is:
+---[RSA 3072]----+
|.+...++.*.+. |
|+o+ o o B . . |
|o. + .. + . o + |
|. . . o+ . . o o |
| . o = .S . |
| .o =... |
| +oooo |
| ..=+E. |
| ..++. |
+----[SHA256]-----+
[root@noufserver-master ~]#
Copy the public key using the ssh-copy-id command to the slave server.
[root@noufserver-master ~]# ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.1.21
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
Number of key(s) added: 1
Now try logging into the machine, with: "ssh 'root@192.168.1.21'"
and check to make sure that only the key(s) you wanted were added.
Step 2: Install LsyncD Package on the AlmaLinux Master Server
Install the lsyncd dependency packages in AlmaLinux using the following yum command.
[root@noufserver-master ~]# yum install lua pkgconfig gcc asciidocHere is the output.
[root@noufserver-master ~]# yum install lua pkgconfig gcc asciidoc
Last metadata expiration check: 0:02:29 ago on Sun 06 Mar 2022 04:37:19 AM UTC.
Dependencies resolved.
=========================================================================================================================================================================
Package Architecture Version Repository Size
=========================================================================================================================================================================
Installing:
asciidoc noarch 8.6.10-0.5.20180627gitf7c2274.el8 appstream 216 k
gcc x86_64 8.5.0-4.el8_5.alma appstream 23 M
lua x86_64 5.3.4-12.el8 appstream 191 k
pkgconf-pkg-config x86_64 1.4.2-1.el8 baseos 15 k
—----
—----
Installed:
adobe-mappings-cmap-20171205-3.el8.noarch adobe-mappings-cmap-deprecated-20171205-3.el8.noarch adobe-mappings-pdf-20180407-1.el8.noarch
asciidoc-8.6.10-0.5.20180627gitf7c2274.el8.noarch atk-2.28.1-1.el8.x86_64 avahi-libs-0.7-20.el8.x86_64
binutils-2.30-108.el8_5.1.x86_64 boost-regex-1.66.0-10.el8.x86_64 cairo-1.15.12-3.el8.x86_64
cpp-8.5.0-4.el8_5.alma.x86_64 ctags-5.8-22.el8.x86_64 cups-libs-1:2.2.6-40.el8.x86_64
docbook-dtds-1.0-69.el8.noarch docbook-style-xsl-1.79.2-9.el8.noarch emacs-filesystem-1:26.1-7.el8.noarch
fontconfig-2.13.1-4.el8.x86_64 fontpackages-filesystem-1.44-22.el8.noarch fribidi-1.0.4-8.el8.x86_64
gcc-8.5.0-4.el8_5.alma.x86_64 gd-2.2.5-7.el8.x86_64 gdk-pixbuf2-2.36.12-5.el8.x86_64
gdk-pixbuf2-modules-2.36.12-5.el8.x86_64 glibc-devel-2.28-164.el8.x86_64 glibc-headers-2.28-164.el8.x86_64
google-droid-sans-fonts-20120715-13.el8.noarch graphite2-1.3.10-10.el8.x86_64 graphviz-2.40.1-43.el8.x86_64
gtk-update-icon-cache-3.22.30-8.el8.x86_64 gtk2-2.24.32-5.el8.x86_64 harfbuzz-1.7.5-3.el8.x86_64
hicolor-icon-theme-0.17-2.el8.noarch isl-0.16.1-6.el8.x86_64 jasper-libs-2.0.14-5.el8.x86_64
jbig2dec-libs-0.16-1.el8.x86_64 jbigkit-libs-2.1-14.el8.x86_64 kernel-headers-4.18.0-348.12.2.el8_5.x86_64
lcms2-2.9-2.el8.x86_64 libICE-1.0.9-15.el8.x86_64 libSM-1.2.3-1.el8.x86_64
libX11-1.6.8-5.el8.x86_64 libX11-common-1.6.8-5.el8.noarch libXau-1.0.9-3.el8.x86_64
libXaw-1.0.13-10.el8.x86_64 libXcomposite-0.4.4-14.el8.x86_64 libXcursor-1.1.15-3.el8.x86_64
libXdamage-1.1.4-14.el8.x86_64 libXext-1.3.4-1.el8.x86_64 libXfixes-5.0.3-7.el8.x86_64
libXft-2.3.3-1.el8.x86_64 libXi-1.7.10-1.el8.x86_64 libXinerama-1.1.4-1.el8.x86_64
libXmu-1.1.3-1.el8.x86_64 libXpm-3.5.12-8.el8.x86_64 libXrandr-1.5.2-1.el8.x86_64
libXrender-0.9.10-7.el8.x86_64 libXt-1.1.5-12.el8.x86_64 libXxf86misc-1.0.4-1.el8.x86_64
libXxf86vm-1.1.4-9.el8.x86_64 libdatrie-0.2.9-7.el8.x86_64 libfontenc-1.1.3-8.el8.x86_64
libgs-9.27-1.el8.x86_64 libicu-60.3-2.el8_1.x86_64 libidn-1.34-5.el8.x86_64
libijs-0.35-5.el8.x86_64 libjpeg-turbo-1.5.3-12.el8.x86_64 libmcpp-2.7.2-20.el8.x86_64
libmpc-1.1.0-9.1.el8.x86_64 libpaper-1.1.24-22.el8.x86_64 libpkgconf-1.4.2-1.el8.x86_64
librsvg2-2.42.7-4.el8.x86_64 libthai-0.1.27-2.el8.x86_64 libtiff-4.0.9-20.el8.x86_64
libtool-ltdl-2.4.6-25.el8.x86_64 libwebp-1.0.0-5.el8.x86_64 libxcb-1.13.1-1.el8.x86_64
libxcrypt-devel-4.1.1-6.el8.x86_64 libxslt-1.1.32-6.el8.x86_64 lua-5.3.4-12.el8.x86_64
mcpp-2.7.2-20.el8.x86_64 openjpeg2-2.4.0-4.el8.x86_64 pango-1.42.4-8.el8.x86_64
pixman-0.38.4-1.el8.x86_64 pkgconf-1.4.2-1.el8.x86_64 pkgconf-m4-1.4.2-1.el8.noarch
pkgconf-pkg-config-1.4.2-1.el8.x86_64 sgml-common-0.6.3-50.el8.noarch source-highlight-3.1.8-17.el8.x86_64
urw-base35-bookman-fonts-20170801-10.el8.noarch urw-base35-c059-fonts-20170801-10.el8.noarch urw-base35-d050000l-fonts-20170801-10.el8.noarch
urw-base35-fonts-20170801-10.el8.noarch urw-base35-fonts-common-20170801-10.el8.noarch urw-base35-gothic-fonts-20170801-10.el8.noarch
urw-base35-nimbus-mono-ps-fonts-20170801-10.el8.noarch urw-base35-nimbus-roman-fonts-20170801-10.el8.noarch urw-base35-nimbus-sans-fonts-20170801-10.el8.noarch
urw-base35-p052-fonts-20170801-10.el8.noarch urw-base35-standard-symbols-ps-fonts-20170801-10.el8.noarch urw-base35-z003-fonts-20170801-10.el8.noarch
vim-filesystem-2:8.0.1763-16.el8_5.4.noarch xml-common-0.6.3-50.el8.noarch xorg-x11-font-utils-1:7.5-41.el8.x86_64
xorg-x11-fonts-ISO8859-1-100dpi-7.5-19.el8.noarch xorg-x11-server-utils-7.7-27.el8.x86_64
Complete!
Before you install the lsyncd package using the yum command, you will need to first install the EPEL repository configuration package using the following command as the lsyncd package is not available in the default repository.
[root@noufserver-master ~]# yum install -y epel-releaseHere is the output.
[root@noufserver-master ~]# yum install -y epel-release
Last metadata expiration check: 0:06:06 ago on Sun 06 Mar 2022 04:37:19 AM UTC.
Dependencies resolved.
=========================================================================================================================================================================
Package Architecture Version Repository Size
=========================================================================================================================================================================
Installing:
epel-release noarch 8-10.el8 extras 22 k
Transaction Summary
=========================================================================================================================================================================
Install 1 Package
Total download size: 22 k
Installed size: 32 k
Downloading Packages:
epel-release-8-10.el8.noarch.rpm 269 kB/s | 22 kB 00:00
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 163 kB/s | 22 kB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : epel-release-8-10.el8.noarch 1/1
Running scriptlet: epel-release-8-10.el8.noarch 1/1
Verifying : epel-release-8-10.el8.noarch 1/1
Installed:
epel-release-8-10.el8.noarch
Complete!
To install the lsyncd package, run the following command.
[root@noufserver-master ~]# yum install lsyncdHere is the output.
[root@noufserver-master ~]# yum install lsyncd
Extra Packages for Enterprise Linux 8 - x86_64 16 MB/s | 11 MB 00:00
Extra Packages for Enterprise Linux Modular 8 - x86_64 5.7 MB/s | 979 kB 00:00
Dependencies resolved.
=========================================================================================================================================================================
Package Architecture Version Repository Size
=========================================================================================================================================================================
Installing:
lsyncd x86_64 2.2.2-9.el8 epel 86 k
Transaction Summary
=========================================================================================================================================================================
Install 1 Package
Total download size: 86 k
Installed size: 205 k
Is this ok [y/N]: y
Downloading Packages:
lsyncd-2.2.2-9.el8.x86_64.rpm 1.4 MB/s | 86 kB 00:00
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 691 kB/s | 86 kB 00:00
Extra Packages for Enterprise Linux 8 - x86_64 1.6 MB/s | 1.6 kB 00:00
Importing GPG key 0x2F86D6A1:
Userid : "Fedora EPEL (8) <epel@fedoraproject.org>"
Fingerprint: 94E2 79EB 8D8F 25B2 1810 ADF1 21EA 45AB 2F86 D6A1
From : /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-8
Is this ok [y/N]: y
Key imported successfully
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : lsyncd-2.2.2-9.el8.x86_64 1/1
Running scriptlet: lsyncd-2.2.2-9.el8.x86_64 1/1
Verifying : lsyncd-2.2.2-9.el8.x86_64 1/1
Installed:
lsyncd-2.2.2-9.el8.x86_64
Complete!
Step 3: Synchronize Local Directories with Remote Using LsyncD
Create a source directory on the master server with this command.
[root@noufserver-master ~]# mkdir master-lsyncdYou can add some files to the source directory using the following command.
[root@noufserver-master ~]# sudo touch master-lsyncd/file{1..25}Here is the output.
[root@noufserver-master master-lsyncd]# ll
total 0
-rw-r--r--. 1 root root 0 Mar 6 05:07 file1
-rw-r--r--. 1 root root 0 Mar 6 05:07 file10
-rw-r--r--. 1 root root 0 Mar 6 05:07 file11
-rw-r--r--. 1 root root 0 Mar 6 05:07 file12
-rw-r--r--. 1 root root 0 Mar 6 05:07 file13
-rw-r--r--. 1 root root 0 Mar 6 05:07 file14
-rw-r--r--. 1 root root 0 Mar 6 05:07 file15
-rw-r--r--. 1 root root 0 Mar 6 05:07 file16
-rw-r--r--. 1 root root 0 Mar 6 05:07 file17
-rw-r--r--. 1 root root 0 Mar 6 05:07 file18
-rw-r--r--. 1 root root 0 Mar 6 05:07 file19
-rw-r--r--. 1 root root 0 Mar 6 05:07 file2
-rw-r--r--. 1 root root 0 Mar 6 05:07 file20
-rw-r--r--. 1 root root 0 Mar 6 05:07 file21
-rw-r--r--. 1 root root 0 Mar 6 05:07 file22
-rw-r--r--. 1 root root 0 Mar 6 05:07 file23
-rw-r--r--. 1 root root 0 Mar 6 05:07 file24
-rw-r--r--. 1 root root 0 Mar 6 05:07 file25
-rw-r--r--. 1 root root 0 Mar 6 05:07 file3
-rw-r--r--. 1 root root 0 Mar 6 05:07 file4
-rw-r--r--. 1 root root 0 Mar 6 05:07 file5
-rw-r--r--. 1 root root 0 Mar 6 05:07 file6
-rw-r--r--. 1 root root 0 Mar 6 05:07 file7
-rw-r--r--. 1 root root 0 Mar 6 05:07 file8
-rw-r--r--. 1 root root 0 Mar 6 05:07 file9
Create a target directory on the slave server.
[root@noufserver-slave ~]# mkdir slave-lsyncdTo set up the LsyncD configuration file,copy the sample configuration to /etc/lsyncd.conf.
[root@noufserver-master ~]# cp /usr/share/doc/lsyncd/examples/lrsync.lua /etc/lsyncd.confAdd the following lines to the configuration file /etc/lsyncd.conf.
[root@noufserver-master master-lsyncd]# cat /etc/lsyncd.conf
----
-- User configuration file for lsyncd.
--
-- Simple example for default rsync.
--
settings{
logfile = "/var/log/lsyncd.log",
statusFile = "/var/log/lsyncd.stat",
statusInterval = 2,
}
sync{
default.rsync,
source="/root/master-lsyncd",
target="192.168.1.21:/root/slave-lsyncd",
rsync={rsh ="/usr/bin/ssh -l root -i /root/.ssh/id_rsa",}
}
Step 4: Start the LsyncD Service and Enable at Reboot
To start the LsyncD service, you can run the following command.
[root@noufserver-master ~]# systemctl start lsyncdTo enable LsyncD at reboot, you can run the following command.
[root@noufserver-master ~]# systemctl enable lsyncdHere is the output.
[root@noufserver-master ~]# systemctl start lsyncd
[root@noufserver-master ~]# systemctl enable lsyncd
Created symlink /etc/systemd/system/multi-user.target.wants/lsyncd.service → /usr/lib/systemd/system/lsyncd.service.
[root@noufserver-master ~]# systemctl status lsyncd
● lsyncd.service - Live Syncing (Mirror) Daemon
Loaded: loaded (/usr/lib/systemd/system/lsyncd.service; enabled; vendor preset: disabled)
Active: active (running) since Sun 2022-03-06 04:58:17 UTC; 3s ago
Main PID: 10950 (lsyncd)
Tasks: 1 (limit: 5834)
Memory: 1.8M
CGroup: /system.slice/lsyncd.service
└─10950 /usr/bin/lsyncd -nodaemon /etc/lsyncd.conf
Mar 06 04:58:17 noufserver-master systemd[1]: Started Live Syncing (Mirror) Daemon.
Step 5: Analyze the Replication and Logs Report
In this article, we used the root user for syncing data. You can change the user name per your requirement.
Using the LsyncD log file /var/log/lsyncd.log, you can find whether the replication is completed or not.
[root@noufserver-master ~]# tail -50 /var/log/lsyncd.logHere is the output.
[root@noufserver-master ~]# tail -50 /var/log/lsyncd.log
Sun Mar 6 04:58:17 2022 Normal: --- Startup ---
Sun Mar 6 04:58:17 2022 Normal: recursive startup rsync: /root/master-lsyncd/ -> 192.168.1.21:/root/slave-lsyncd/
Sun Mar 6 04:58:17 2022 Normal: Startup of /root/master-lsyncd/ -> 192.168.1.21:/root/slave-lsyncd/ finished.
Sun Mar 6 05:08:01 2022 Normal: Calling rsync with filter-list of new/modified files/dirs
/file1
/file2
/file3
/file4
/file5
/file6
/file7
/file8
/file9
/file10
/file11
/file12
/file13
/file14
/file15
/file16
/file17
/file18
/file19
/file20
/file21
/file22
/file23
/file24
/file25
Sun Mar 6 05:08:01 2022 Normal: Finished a list after exitcode: 23
Sun Mar 6 05:09:09 2022 Normal: --- TERM signal, fading ---
Sun Mar 6 05:09:09 2022 Normal: --- Startup ---
Sun Mar 6 05:09:09 2022 Normal: recursive startup rsync: /root/master-lsyncd/ -> 192.168.1.21:/root/slave-lsyncd/
Sun Mar 6 05:09:09 2022 Normal: Startup of /root/master-lsyncd/ -> 192.168.1.21:/root/slave-lsyncd/ finished.
You can view the LsyncD status report using the stat file /var/log/lsyncd.stat.
[root@noufserver-master lsyncd]# cat /var/log/lsyncd.statHere is the output.
[root@noufserver-master ~]# cat /var/log/lsyncd.stat
Lsyncd status report at Sun Mar 6 05:09:11 2022
Sync1 source=/root/master-lsyncd/
There are 0 delays
Excluding:
nothing.
Inotify watching 1 directories
1: /root/master-lsyncd/
Wrapping Up
If you are looking for a server to install and configure LsyncD on Almalinux or if you are uncomfortable with performing any of the steps outlined above, Liquid Web has what you need. Our Support Teams are filled with experienced Linux technicians and talented system administrators who have intimate knowledge of multiple web hosting technologies, especially those discussed in this article.
We offer Dedicated Server and VPS Hosting options. In addition, our skilled team provides 24/7/365 support and monitoring services so that you can focus on your websites. Contact our team today to learn more.
Related Articles:
About the Author: Mohammed Noufal
Mohammed Noufal has worked as a senior server administrator for 8+ years. He can be found on LinkedIn to know more or connect.
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