File Locking under Mac OS X

Apple OS X and Omnis LogosMac OS X servers and some other UNIX servers do not fully support the file based byte locking employed by Omnis in a cross platform manner, and therefore require the ODB software to operate safely.

Using Omnis with Mac OS X version 10.4

After further testing in Engineering, we are now advising all customers to make use of the Omnis Databridge (ODB) when connecting to an Omnis datafile situated on a system running Mac OS 10.4.x (Tiger). This is regardless of the operating systems running on the client machines, so it applies even if all the client machines are running the same operating system. Similarily, if any client machine is running Mac OS 10.4 , the ODB must be used on the datafile server, regardless of the server platform or operating system.

We will of course test any further release of 10.4 from Apple and inform our customers if this advice can be revoked.

The remainder of this note relates to using Omnis under Mac OS X version 10.2 (Jaguar) and the Omnis datafile.

Omnis Studio and OS X Server

If your datafile is on OS X server, a mix of Windows and Mac clients will cause corruption. All Windows or all Mac clients is fine. The reason is that Mac uses Apple File Protocol (AFP) and PC uses Samba (SMB). Unfortunately the two protocols ignore each other.

This means we must advise you not to use the Omnis datafile, either with DML or Omnis SQL, on OS X server in a mixed environment with Omnis Studio 3.2.x or earlier.

If the datafile is on a machine running NT, Win2000/2003/XP or Novell NetWare, mixed OS X, OS 9 and PC clients can access the datafile without causing corruption, providing the Mac connection is via AFP, not SMB.

A mix of OS X clients and OS 9 clients will work successfully with an Omnis datafile on an OS X server, provided the connections are via AFP.

Omnis 7 client running on OS X Classic mode (OS 9 emulation)

In previous versions of OS X client, the Classic mode, which is essential to Omnis 7, ignored locks. So any selection of clients that included OS X would corrupt the datafile, regardless of where it was placed.

Mac OS X 10.2 (Jaguar) fixes this issue. That means that as long as you obey the rules regarding the datafile under point 1 (so do not put the datafile on OS X server in a mixed client situation and do use AFP), this Omnis 7 problem is resolved.

A mix of OS X clients and OS 9 clients will work successfully with the datafile on an OS X server, provided the connections are via AFP.

September 2002 (updated August 2006)