What is the best version of Jira 7.x for upgrading from 6.1.5?

[Kieu Anh]

I have a system base on Jira Software version 6.1.5 installed on Window Server 2008 R2 and DB is MS SQL Server. I want to upgrade to 7.x.x version of Jira.

So, what version that should be choose for upgrading?

And, can I upgrade directly from 6.1.5 to 7.x.x without jump step by step through other middle version (example: from 6.1.5 to 6.4, then from 6.4 to 7.0, then from 7.0 to 7.x.x)?

If you want, I can list of all plugin (addons) installed in current system.

Please give me an advice, thanks for your reading

[Nic Brough -Adaptavist-]

The main answer is simple - "use the latest main version". 

By "main", I mean the middle digit of the version.  I would tend not to install x.y.0 in production because there's sometimes teething problems in a .0 release that quickly get fixed in x.y.1 and x.y.2, but for x and y, the "best" version is almost always "latest available".  We won't talk about the horrible design mistake made in 7.4.z that was quickly fixed in 7.5 - that does happen sometimes, but it's rare.

For the upgrade, absolutely not.  You must go from 6.1 to 6.4, then 7.0, and then 7.latest.  There is upgrade code in 7.0 for handling data changes from 6.x that does not exist in 7.1 and above, and 7.0 can only handle data from 6.4 properly, not 6.3 or lower.  (This said, the data is minor and optional, and you *might* get away with 6.4 to 7.latest.  But there's no way of knowing without doing it and then doing extensive testing.   It's easier and safer to step through the versions)

[Kieu Anh]

Thanks for your answer. By reviewing plugins existed in current environment, some of them cannot run in Jira 7.5. So, can you suggest other version before 7.5? For example, 7.4.x, or 7.3.x, because in your opinion, I shouldn't use x.y.0.

[Nic Brough -Adaptavist-]

Any of them, take the latest one you can run your add-ons on.