In the output of "ps aux" there is a high number of zombie sh processes, for example:
16 admin 20558 1450 0.0 0.0 0 0 Z 00:00:00 Oct 07 | \_ [sh] < defunct >
17 admin 20587 1450 0.0 0.0 0 0 Z 00:00:00 Oct 07 | \_ [sh] < defunct >
20 admin 21149 1450 0.0 0.0 0 0 Z 00:00:00 Oct 07 | \_ [sh] < defunct >
15 admin 21157 1450 0.0 0.0 0 0 Z 00:00:00 Oct 07 | \_ [sh] < defunct >
The zombie processes are child process of /bin/confd.
The real name option is configured for the users:
passwd:User1:realname U1
passwd:User2:realname U2
Restarting confd resolves the issue.
Cause
When adding users via clish command line, confd creates a child process but does not release the resources used. This creates zombie process under confd.