Hey @khineminn
I would say what @AkosBakos sent is EXCELLENT, but I will also try explain it in simple terms, if you will.
Config backup, say if you were to go to clish and run save configuration config.txt (or whatever filename you give it), it would generate simple txt file in whatever dir you were in. Sao if you see my example below, it was /home/admin
[Expert@CP-FW-01:0]# pwd
/home/admin
[Expert@CP-FW-01:0]# ls
config.txt test.txt
[Expert@CP-FW-01:0]# ls -lh
total 12K
-rw-r--r-- 1 admin config 7.2K Aug 28 13:45 config.txt
-rw-rw---- 1 admin root 5 Aug 22 11:29 test.txt
[Expert@CP-FW-01:0]#
This file simply lets you copy the config back into clish if you say build new server or reinstall old one, its very convenient.
Now, if you get migrate_export, it will contain all the config that you can import later into another mgmt with same CP version.
If you want EVERYTHING backed up, then run snapshot. However, personally, I always prefer backups, because even though it does not restore the hotfix, its not a big deal, because 99% of the time, jumbo hotfixes matter for the gateways, not the management.
Hope that helps.
Andy