db2ckpwd, db2wdog为什么需要root用户运行.

db2ckpwd:
db2ckpwd is the password checking daemon that deals with user
authentication. This process is used to confirm that the id exists and
has a right to be on the box. If the process if not a root process, only
local connections will be allowed to the database because the id is
already on the box. To make the OS API calls necessary to determine if
the user has the right to be on the box, DB2‘s db2ckpwd must run as
root. If it is not started as root, it will not have permissions to make
the API calls, and it will return an SQL 30082 rc=24 error. Also since
the db2ckpwd must su to root, in order to run as root, the db2ckpw file
will need to have the su bit set, and the file system must be mounted so
that su‘ing is allowed.

db2wdog:
The db2sysc spawns a db2wdog process. Db2wdog process is used to handle
abnormal termination of the db2sysc process. Db2wdog process monitors
the db2sysc process and when the db2sysc process dies due to, say a
crash, the db2wdog then kicks in and terminates all other process for
that instance. If db2wdog was to be run as instance owner it would die
when the db2sysc process dies as well. So running as root and not
running as a child process of the instance owner db2sysc process, the
db2wdog can actually do the cleanup of all db2 process in conditions
where an abnormal termination of the db2sysc process is encountered.