Please refer a document regarding the upgradation of jira from 7.3 to 7.12 in Linux environment

[kedar]

Please refer a document

[Nic Brough -Adaptavist-]

First hit on any search engine is the standard upgrade documentation you need to start with.  https://confluence.atlassian.com/adminjiraserver/upgrading-jira-applications-938846936.html

[Christos Moysiadis]

Here is your link.... https://confluence.atlassian.com/adminjiraserver073/installing-jira-applications-on-linux-861253030.html

I advice you to read the documentation in each upgrade seperately, e.g v7.3 to v7.4 , v7.4 to v7.5 and so on! So you are full informed about the changes which made i each version

Then you can determine what is the best way for you to make the upgrade!

Best regards

CM