See explanation below.
1. chmod g+s /data 2. Verify using: ls -ld /data Permission should be like this: drwxrws--- 2 root sysadmin 4096 Mar 16 18:08 /data If SGID bit is set on directory then who every users creates the files on directory group owner automatically the owner of parent directory. To set the SGID bit: chmod g+s directory To Remove the SGID bit: chmod g-s directory