I have been using Unionfs off and on for Puppy Linux. Mostly I have used Aufs, as whenever I have used Unionfs, I have run into some problems.
Recently, however, I was quite happy with Unionfs 2.5.10, it seemed to be behaving very nicely, and I released a version of Puppy Linux (Wary 5.2.2) using it. However, yesterday someone reported a serious problem, and I have been able to reproduce it. This brings back memories. It is the old problem with the '.wh.__dir_opaque' whiteout file. Over the years we developed code to manage this, as it caused us some trouble. The fundamental problem is that Unionfs is following the standard specification that the .wh.__dir_opaque file should be created when a directory is created, but this can cause so much trouble. Aufs on the other hand, does not create this whiteout file, unless it specifically has to block a lower layer. This is sensible, and works. Anyway, here is my blog report on the disaster that we have experienced with the .wh.__dir_opaque file: http://bkhome.org/blog/?viewDetailed=02777 ...the thing is though, the 'rm' operation should not fail in this situation. There is a bug in Unionfs that is allowing rm to fail. Regards, Barry Kauler _______________________________________________ unionfs mailing list: http://unionfs.filesystems.org/ [email protected] http://www.fsl.cs.sunysb.edu/mailman/listinfo/unionfs
