How to take incremental Backup using tar


tar provides following options to handle incremental backup

 –listed-incremental=snapshot file (-g snapshot file)

–incremental (-G)

Examples

[root@localhost~]# tar –create –file=archive1.tar listed-incremental=/var/log/usr.snar /usr

 Above command will create archive1.tar as incremental backup of /usr file-system, additional metadata will stored in file/var/log/usr.snar file. If /var/log/usr.snar file not exist it will get created, the created archive will then level 0 backup.

Now suppose for the same example, if /var/log/usr.snar exist. Then above given will check which files get modified and only those files stored in archive, so that will be level 1 backup.

 So the best option is take level 0 (full) backup first as following 

[root@localhost~]# tar –create –file archive1.tar –listed-incremental=/var/log/usr.snar

copy that file 

[root@localhost~]#cp /var/log/usr.snar /var/log/usr.snar-1

Then take incremental backup as follows 

[root@localhost~]#tar –create –file archive2.tar –listed-incremental=/var/log/usr.snar

To extract content from backup we also have to follow same steps which followed at the time of backup. In our example the procedure will be as follows
[root@localhost~]# tar –extract –listed-incremental=/dev/null –file=archive1.tar
Followed by
[root@localhost~]#tar –extract –listed-incremental=/dev/null –file=archive2.tar 

About Alex Hunt

Hi All I am Manish Kumar Jha aka Alex Hunt. I am currently working in VMware Software India Pvt Ltd as Operations System Engineer (vCloud Air Operations). I have around 5 Years of IT experience and have exposure on VMware vSphere, vCloud Director, RHEL and modern data center technologies like Cisco UCS and Cisco Nexus 1000v and NSX. If you find any post informational to you please press like and share it across social media and leave your comments if you want to discuss further on any post. Disclaimer: All the information on this website is published in good faith and for general information purpose only. I don’t make any warranties about the completeness, reliability and accuracy of this information. Any action you take upon the information you find on this blog is strictly at your own risk. The Views and opinions published on this blog are my own and not the opinions of my employer or any of the vendors of the product discussed.
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