Modify but no delete permission

[Getekid]

Hello,

I am using FreeNAS 8.3.1 on a ZFS file system and I would like my users to be able to modify their files but at the same time without having the right to delete them. Is there a set of permissions where I could achieve that?

I 've search around the web and saw many arguments like "If the user can modify the file, he could delete all it's content and that would be equal to deleting it", but still we had a lot of cases of accidental deletion of files (and not content) so the above would be really useful for us.

Thanks in advance

 

[SweetAndLow]

Snapshots or if you're using cifs you can turn on the trash.

 

[Dusan]

I am using FreeNAS 8.3.1 on a ZFS file system and I would like my users to be able to modify their files but at the same time without having the right to delete them. Is there a set of permissions where I could achieve that?

You need to use Access Control Lists. It gives you separate append_data / write_data / delete / delete_child permissions. See this thread for more information: One Folder, 2 Groups needing different permissions?

 

[fracai]

What if the user truncated the file to zero bytes? Or writes zeroes over the whole thing?

Wouldn't a better strategy be to rely on snapshots, backups, or write protect the files and require users to work on copies?

I know I'm not providing any solutions, I'm just looking to understand the goals.