LePhasme wrote:

Dreamhost answered to my ticket saying that the processes were killed because they used too much RAM.
I didn't even saw it...
I think I wont be able to use piwigo.

Just in case you missed my answer the day before, I'd like to repeat:
"I was told that regardless of unlimited space and bandwidth they are still trying to limit activity of each user to avoid potential abuse. I have number of projects under my account, and two of them are quite heavy on space usage, so it looked like I have reached the limit, and the server was halting scripts.

The solution was creating new user sub-account within my existing account and moving a project or two over, thus taking some load off from my initially single user account. It has not changed my doing business with DreamHost, not a penny extra."