The hidden file attribute is not being saved because you are using a linux based NAS and connecting using Samba. Because of how the drobo configures samba by default, the hidden attribute is not supported (ie, not saved) so when you look at the file properties again the hidden attribute shows as unchecked. Samba needs to be configured to treat hidden files correctly, you can look at this for all the details: http://www.samba.org/samba/docs/using_samba/ch08.html
Before you think you can easily enable this, it’s not something easy to just turn on for the Drobo FS and here is why:
- the settings are in /mnt/DroboFS/System/samba/conf which is a regenerated file so any changes you make WILL be lost at some point
- the drobo configures files with a default mode of 0777 and since samba uses the execute bits to store file attributes, essentially the drobo is configured to default every file as potentially a “hidden+system+readonly” file (if you enabled these in samba), so you would need to change the default mode as well
I’m not saying that it’s not possible to do this yourself, I’m just saying that it would be difficult and may not be worth the effort. It will also mean that most likely won’t be able to use the Dashboard to manage your shares without blowing away your changes.
I would suggest that you open a support case with DRI and state that “windows file attributes don’t work on the Drobo FS” and hope you are lucky enough to get them to enable this in the future. Assuming support will not fix it immediately, I would also log it as a feature request.