Egencache

egencache is a software tool that rebuilds metadata information for the Portage tree.

Metadata for the Portage tree comes with tarballs and can be downloaded using the  command (via rsync), but will not be downloaded when using cvs checkout for your Portage sync method.

Installation
Since almost every Gentoo install comes with Portage by default, you should already have egencache installed on your system. Run a quick test by issuing the following command to a root terminal:

If you did not receive usage instructions then the tool is not installed. You can (re)install Portage by following the install instructions posted on the Portage page.

How to use
In order to rebuild the metadata cache on your system you can issue this command:

Of course adjust the number of jobs to be appropriate to your system. The "safe" metric to use with jobs is