I am looking to get some help in migrating all jira data from one cloud instance to a new one.

[Preetham Bhat]

My organization has a legacy instance which contains jira and confluence data. I am tasked with migrating them to the new instance. How do I do this without loosing any data on tickets, history, comments etc ?

[Brant Schroeder · Accepted solution]

@Preetham Bhat Welcome to the Atlassian community

Here is what is copied https://support.atlassian.com/organization-administration/docs/what-product-data-is-copied/ 

Here are instructions on how to migrate. 

• https://support.atlassian.com/organization-administration/docs/copy-jira-data/ 
• https://support.atlassian.com/organization-administration/docs/copy-confluence-data/ 

[ELFAPP Technologies]

You can export your data and import it into another cloud environment using various methods. This document shows the available options, JSON and the Jira cloud export should give you the ability to retain the things you need based on your requirements.

[Preetham Bhat]

I read somewhere that jira cloud export will overwrite the data in the new instance. Any inputs on which of the options can help me retain granular data on tickets like attachments, history etc ?