HP CIFS Server Administrator's Guide Version A.03.01.02 (5900-1766, September 2011)

• hosts deny
• hosts equiv
• preload modules
• wins server
• vfs objects
• idmap backend
Other Samba Configuration Issues
Translate Open-Mode Locks into HP-UX Advisory Locks
The HP CIFS Server A.02.* and A.03.* 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.
NOTE: Starting with the Samba 3.0.25 version, the Change Notify Timeout feature is deprecated.
The Change Notify Timeout feature is replaced with the Change Notify feature. This new feature
depends on Linux iNotify, which is not available in HP-UX operating systems.
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.
Special Concerns when Using HP CIFS Server on a Network File System (NFS) or a
Clustered File System (CFS)
Both NFS and CFS provide file system access to unique file storage from multiple systems. However,
controlling access to files, particularly files open for write access, from multiple systems poses
challenges. Applications are not necessarily network or cluster-aware. Applications may not be
Other Samba Configuration Issues 31