This is R81.10 upgrade package which was locally imported before the upgrade to R81.10 using CPUSE. During the import process (using clish command "installer import local <PATH> or from WebUI), the CPUSE agent will copy the package to the CPUSE repository. After successful import, you can safely delete the original package in <PATH> while the package is still available within CPUSE and ready to upgrade or perform clean install.
Once you have upgraded or clean installed the package, you can also delete the package saved by CPUSE using command "installer delete {<Package_Number> | <Package_Name>}". As mentioned by Andy, do NOT manually delete the package from CPUSE repository folder !
In fact, you need 6,8G (2 x 3,4G) available on your disk. It might be issue when running low on disk space.
Kind regards,
Jozko Mrkvicka