As a newbie to DB2 I have a strange problem on a zSeries linux box I
hope someone can answer.

I have created a linux user,

user=mytest
pw=mytest

who is the instance owner and has created a database called mydatabase
with our application schema.

When entering db2 I can enter ok via,

db2> connect to mydatabase

This allows me access to the db where I can load/view data in the
normal fashion. Trouble is we want to do this via an application which
requires us to enter (understandably) a username and password.
Everything I try I ends up with;

[IBM][CLI Driver] SQL30082N  Attempt to establish connection failed
with security reason "24" ("USERNAME AND/OR PASSWORD INVALID").
SQLSTATE=08001

So I thought a typo had been made when entering the password when
creating the user. So I went back into db2 and tried;

db2>connect to mydatabase user mytest using mytest

and low and behold I get;

SQL30082N  Attempt to establish connection failed with security reason
"24"
("USERNAME AND/OR PASSWORD INVALID").  SQLSTATE=08001

Exactly the same error although the password is correct for the linux
user as it is how I logon to the machine.

The question is why can't I login to db2 using this password. Is there
a way to alter or view the password using the root acount ?

Is there a procedure for checking the authenticity/status of users
allowed to login to a given database ?

Any help much appreciated.