When you say the "report option in Moodle only retrieves data from the last six months" do you mean that your site is set to truncate the logs after 6 months? (In Site admin > Plugins > Logging > Standard logs :: Keep logs for. ). If so then that makes sense as you would only see the last six months of dates in the pull down menu in Reports > Logs to choose a date. If that is what is happening, then that old data is no longer in the
database.
If you did a course backup and you checked the "Include course logs" option, then when you restore the course it will restore all those log entries as well with their original dates and times. (If the backup did not include those course logs, then there are no old logs to restore.)
_However_, the very next time the site runs the task to truncate the logs older than 6 months, it will then delete all those restored entries with those dates older than 6 months. By default his task runs once a day.
So, if you need to view those old dates for a while, then you might consider temporarily setting the Logs not to delete, until you can get that old data out and save it, then set it back to truncate at 6 months.
