Conversion Between Inline and Outline JFS2 Filesystem Logs

Question

Can you convert a JFS2 filesystem with an outline log (i.e. external log logical volume) to one with an inline log?

Answer

No, JFS2 filesystems using one type of log cannot be changed to use another. If a filesystem is created to use a log logical volume, for example /dev/loglv00, it cannot be changed to use an inline log.

In the same respect, a JFS2 filesystem using an inline log cannot be successfully changed to point to an outline log. While this may seem to work it will not survive exportvg/importvg.

The chfs man page has this to say about inline and outline logs:

For a file system using INLINE log, this option does not support switching logs between INLINE and OUTLINE log. Currently, to switch from inline log to outline log (or vise versa), the file system has to be removed and recreated.