will running jira cloud migration process lock out access to existing server install?

[John Bell]

During the cloud migration process will my users still be able to access the server install of jira we currently use?

[Andy Heinzer]

Hi John,

Using the Jira Cloud migration assistant app in Jira Server does not lock out the server instance during the migration.  Because of this there is a note about such changes over in https://support.atlassian.com/migration/docs/use-the-jira-cloud-migration-assistant-to-migrate/

Changes on server before migrating
If you make any changes on your server site, wait at least 10 minutes before migrating to allow all data to be updated.

I hope this helps.

Andy