inf1 from PSX-Scene has posted a tutorial on how to play PS3 game dumps containing 4gb+ files via external HDD. Many PS3 games use a type of compression known as .PSARC, an archived format for PS3, similar to WinRAR or WinZIP. The logical thing to do is simply extract them, and copy them over in smaller size .
There games that do not have PSARC compression so this method would obviously not work. Reply back with games you have, and found that have these file formats and we will try to keep a list here of all the games this works with.
1) Download PSARC Extractor
2) Extract zlib.net.dll and PSARC.exe to any folder.
3) Find any files more than 4Gb for example PS3_GAMEUSRDIRbuildmainpak22.psarc (5 596 444 529 byte)
4) Copy pak22.psarc into zlib.net.dll and PSARC.exe directory.
5) Extract pak22.psarc (just drag-n-drop pak22.psarc to PSARC.exe)
6) Now copy pak22 folder with extracted files to gamefolder PS3_GAMEUSRDIRbuildmain
7) Now you can delete pak22.psarc.
8.) copy PS3_GAME folder with game to your external fat32 usb hdd GAMEZUncharted2
9) use backup manager to load game, should work fine.
Thanks to lewenberg for news tip.