HP CIFS Server 3.0d Administrator's Guide version A.02.02 (Edition 5)

Installing and Configuring the HP CIFS Server
Other Samba Configuration Issues
Chapter 2 39
Other Samba Configuration Issues
Translate Open-Mode Locks into HP-UX Advisory
Locks
The HP CIFS Server A.02.* versions can translate open mode locks into
HP-UX advisory locks. This functionality prevents HP-UX processes
from obtaining advisory locks on files with conflicting open mode locks
from CIFS clients. This also means CIFS clients cannot open files that
have conflicting advisory locks from HP-UX processes.
You must change the map share modes setting in smb.conf to yes to
translate open mode locks to HP-UX advisory locks. The default setting
of map share modes is no.
Performance Tuning using Change Notify
This section describes performance tuning using the Change Notify
feature and internationalization.
The Samba Server supports a new feature called Change Notify. Change
Notify provides the ability for a client to request notification from the
server when changes occur to files or subdirectories below a directory on
a mapped file share. When a file or directory which is contained within
the specified directory is modified, the server notifies the client. The
purpose of this feature is to keep the client screen display up-to-date in
Windows Explorer. The result: if a file you are looking at in Windows
Explorer is changed while you are looking at it, you will see the changes
on the screen almost immediately.
The only way to implement this feature in Samba is to periodically scan
through every file and subdirectory below the directory in question and
check for changes made since the last scan. This is a resource intensive
operation which has the potential to affect the performance of Samba as
well as other applications running on the system. Two major factors
affect how resource intensive a scan is: the number of directories having
a Change Notify request on them, and the size of those directories. If you
have many clients running Windows Explorer (or other file browsers) or
if you have directories on shares with a large number of files and/or
subdirectories, each scan cycle might be very CPU intensive.