Upgrade CB from 3.1.2 to 6.0

Greetings!

I would like to know the safest upgrade path from 3.1.2 to 6.0 using the offline mode? I see that I have a few options and please correct me where I am wrong. Currently using Enterprise edition for RH 6.6

Should I do a straight upgrade from 3.1.2 to 6.0 or should it be done in steps (i.e. 3.1.2 to 4.5 to 5.6 and finally to 6.0)?
What is the guideline for offline mode? Should I perform a backup at 3.1.2 using ccbackup or ccbackupmgr? Should I simply shutdown the CB server though

sudo  service couchbase-server stop

and then proceed to install the desired version? I am unable to find the step-by-step guide for upgrade in offline mode.

Thank you

Hi mpc120,
Thanks for using our products.
To upgrade from 3.1.2 to 6.0, you need to upgrade cluster to 4.x ==> 5.x ==> 6.0.x as show in support upgrade path in this document https://docs.couchbase.com/server/6.0/install/upgrade.html
To perform offline upgrade, you could follow the instruction on this page https://docs.couchbase.com/server/6.0/install/upgrade-offline.html

Since upgrade process relating to data management, you need to backup your data first before doing any upgrade. For cluster 3.x, instruction how to backup is here https://developer.couchbase.com/documentation/server/3.x/admin/Tasks/backup-cbbackup.html
If you have any question, drop me a line a thuan at couchbase dot com
Thanks