help: to limit a folder`s size without using quotas
 

Friends, could anybody there give me a light, please, to solve the following problem: I need a way to limit the size of a folder, but without using group or user quotas... is there a good solution?

For example, I want to avoid that folder X grows up more than 100MiB, no matters who writes to the folder...

If there is no such way, maybe do you think that it is possible to create a new user account just to control the size of the folder X? I mean to put this new user as the owner of the folder X and allow any access to the folder... Do you think that, if someone writes to the folder, the quota of the new user would be consumed and reach an unbreakable limit?

thanks in advance

maybe put the folder on a 100MB partition?

solved
 

just to give a feedback: a loop device was a really good idea... to every folder that I want to limit its size I create an image of a file system with the right size... []'s