Hello there!

The story sounds like this: a public share with no restrictions, every user has it's own folder there and in time it becomes messy and very large in gigs.

I have set up a simple find and delete script for files older than X days.

The problem is that some of the files that are send in this share are transfered from an archive server and creation/modified date remains the same when copied and the age of them could be a year ago or older and they get deleted over night by the script.
For performance reasons the raid is mounted with noatime in fstab.

Do you see any solution to this problem except enabling atime?

I'm thinking at some more advanced script that writes the list of added files once a day and marks them for deletion after some time.

Thanks in advance

Test the ctime (inode change time) rather than relying on atime. The inode change time will always show the last time something about the file changed, and that includes creation, altering of content, number of links, permissions, ownership, ... .

Thank you!

ctime does the job