We have a project in Jira Service Management under which there are about 12000 issues.
These issues contain attachments, links, internal notes, attachments + links in internal notes, as well as around 10 custom fields we have created.
We would like to migrate the whole project (all issues) to Jira Software instance without losing any information we have.
Please advice the best way to do so if possible and the problems we may confront.
Which solution could work? Export/Import .xml? or with backup and restore backup?