JIRA, Fisheye/Crucible and anything that depends on those services will be affected.
Minkata and the repositories will not be impacted and will remain available.
I don't have a good time estimate as to how long this will take due to the size of the upgrade.
I will attempt to confine the downtime to this weekend
![Cool 8-)](./images/smilies/icon_cool.gif)
_R