Hi Guys.. i was having trouble adding a lot of images at the same time.. (like 6000 images) using ftp.. the album was getting breaked...

Then i started doin lots of 500 and it was OK!

My question is in the future when i use "Refresh database" it will try to process all images in the folders again? This will break albums again!?

i think this happens because of max_execution_time or memory_limit

The database refresh should not break anything. Zenphoto's albums management is file system based which is why you can upload via FTP. All changes are then matched with the database. If you remove albums via FTP Zenphoto will know that on request only. For example someone visits site or backend. The database refresh matches filesystem with the database directly.

Read here how image discovery (and caching) works:
http://www.zenphoto.org/news/caching
Adding 6000 images at a time might very well overload any normal server.

thank you!