Specifications
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# /opt/nessus/sbin/nessuscli fetch --register <activation code> 
6.  Reindex Nessus plugins. This may take up to 15-20 minutes, depending on your system. 
# /opt/nessus/sbin/nessus-service -R 
7.  Once Nessus completes the reindexing process, restart the Nessus service: 
# /sbin/service nessusd start 
8.  Log in to your Nessus scanner using the Nessus UI at https://yoursystem:8834.  
9.  Once you confirm your new system is working correctly and all the files are migrated, go through the removal 
process on the original system listed in the Mac OS X section of this document. 
For backing up and/or restoring a complete Nessus installation, please contact Tenable Support if you have any 
questions. This will help to ensure there are no deviations from a normal installation that may prevent critical data from 
being maintained. 
Windows 
Upgrading 
Upgrading from 5.x to 6 is straightforward and does not require any special considerations. Instructions are below. 
Upgrading from 5.x 
Download the latest version of Nessus from the Nessus download page or through the Tenable Support Portal. Confirm 
the integrity of the installation package by comparing the download MD5 checksum with the one listed in the product 
release notes. 
When upgrading Nessus from a 5.x version to the Nessus 6 distribution, the upgrade process will ask if the user wants to 
delete everything in the Nessus directory. Choosing this option (by selecting “Yes”) will mimic an uninstall process. If you 
choose this option, previously created users, existing scan policies, and scan results will be removed, and the scanner will 
become unregistered. 
Click on “Yes” to allow Nessus to attempt to delete the entire Nessus folder along with any manually added files or “No” to 
maintain the Nessus folder along with existing scans, reports, etc. After the new version of Nessus is installed, they will 
still be available for viewing and exporting. 
The user may also be prompted to reboot the system depending on the version being installed, and the version currently 
on the system: 










