chown not working

After more digging, I found out the chown wouldn't work in the USB hard drive share that is attached to the ReadyNAS. Those regular shares created in the NAS hard drive are fine.

Following is the chown output made to the folder in a regular share "data".

whale:/data# chown peter:users public
whale:/data# ls -l
total 48
drwxrwx--- 3 root users 16384 Jan 7 14:11 Network Trash Folder
drwxr-xr-x 2 peter users 16384 Jan 7 01:13 public
drwxrwx--- 3 root users 16384 Jan 7 14:11 Temporary Items
whale:/data#

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Following is the chown output made to the folder in the USB hard drive share "USB_HDD_2"


whale:/USB_HDD_2# mkdir testfolder
whale:/USB_HDD_2# ls
media System Volume Information testfolder
Network Trash Folder Temporary Items
whale:/USB_HDD_2# ls -l
total 4
drwxrwxrwx 1 root root 4096 Jan 7 01:16 media
drwxrwxrwx 1 root root 0 Feb 27 2011 Network Trash Folder
drwxrwxrwx 1 root root 0 Mar 8 2011 System Volume Information
drwxrwxrwx 1 root root 0 Feb 27 2011 Temporary Items
drwxrwxrwx 1 root root 0 Jan 7 14:58 testfolder
whale:/USB_HDD_2# chown peter:users testfolder
whale:/USB_HDD_2# ls -l
total 4
drwxrwxrwx 1 root root 4096 Jan 7 01:16 media
drwxrwxrwx 1 root root 0 Feb 27 2011 Network Trash Folder
drwxrwxrwx 1 root root 0 Mar 8 2011 System Volume Information
drwxrwxrwx 1 root root 0 Feb 27 2011 Temporary Items
drwxrwxrwx 1 root root 0 Jan 7 14:58 testfolder
whale:/USB_HDD_2#

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Both are using root login. Not sure why there is any different. So I check the share access configuration in the ReadyNAS Frontview. Everything seems right, except the ownership. In the Share Listing->USB Share->Advance Option, the [Share Folder Owner] and [Share Folder Group] are always assigned to "root". No matter what I changed it would always revert back to "root" after saving.

I'm not sure if this is the root cause. I also don't remember how to create this USB Share since it was long time back.

Anyone has any idea on how to fix this?

Many thanks.