CSV image import issue - from 4GB backup to 50G restored files

My detailed and thumbnails folder have a total of 50G fo 2000 products, so I decide it to backup and restore images to see the result. I made images backup using Admin-export-images , so image backup went to /var/files/exim/backup folder resulting in 4G size. I deleted detailed and thumbnails folders and started the restore, the result was the same size ,the restore toke several hours while my website hardly loaded and the newly created detailed and thumbnails folder have 50G even if /var/files/exim/backup folder have only 4G. How is that possible ? CSV file have 115000 lines. What is the problem and how to fix it ?

It sounds like you re-imported both Detailed and Thumbnail images. You only need to import the Detailed images because the system will create the Thumbnail automatically.

Try to delete all the thumbnails that were generated automatically. To do it, add &ct to the URL at any page in the admin panel. E.g.

https://domain.com/admin.php?dispatch=products.manage&ct

But the detailed folder had 45G while Thumbnail folder only 5G. I also deleted both detailed and Thumbnail before the import.