I tried the following procedure many times but still haven't found an explanation, so I'm hoping to find someone who can do that for me.

As root, in tty1 I create a new user (useradd johndoe) and assign him a password
(passwd johndoe). Then I login as johndoe in tty2. Then I try, in tty1, to delete the user by means of the command "userdel johndoe", which is obviously not possible because the user is logged in. In tty2 I logout (exit) and then try again the deletion in tty1, with no problems at all.

THEN I start it all over again with a little difference. After logging in in tty2 as johndoe, in tty1 I issue the command "ps -u johndoe" to find out the PID of johndoe's shell. Then I issue the command "kill -s 9 xxxx" where xxxx is the previously found PID. I check tty2 and see that the johndoe's bash session has actually aborted and the terminal prompts for another login as expected. At this point, however, if in tty1 I issue the command "userdel johndoe" I always get an error message saying that "user johndoe is currently logged in.

How can that be explained (and worked around)?

Thanks

hi,

try
it seems that there are files open for this user.