HP CIFS Server 3.0k Administrator's Guide version A.02.04

Winbind Supports Non-blocking, Asynchronous Functionality
For HP CIFS Server A.02.03 or later, winbind supports an almost completely non-blocking,
asynchronous request/reply implementation (with the exception of user and group enumeration).
With this new enhancement, winbind provides better scalability in large domain environments
and on high-latency networks.
Winbind uses the blocking, synchronous behavior when enumerating users and groups. Set
both winbind enum users and winbind enum groups to No to force winbind to suppress
the enumeration of users and groups.
Winbind Supports Non-blocking, Asynchronous Functionality 113