OmegaPhil: > The reason I focussed on the refcnt is because I'd done the obvious > basic stuff - the aufs mount point (/mnt/bulk_storage) only exists for > the purpose of mounting the aufs volume, so for it to be 'busy' for no > reason is ridiculous. To get to the point where I could umount the aufs > volume, by definition no programs are using it - obviously the first > thing I did when I initially came across the problem was to 'sudo lsof > /mnt/bulk_storage' which came up with nothing.
How about /proc/mounts? Does it show that aufs is unmounted? If you run "stat -f /mnt/bulk_storage", what fs-type does it show? I really believe you should confirm your /mnt/bulk_storage is correctly unmounted as a first step. I know some people always add "-l" option blindly when they unmount something. As you might know, such umount command may not fully unmount it while it looks succeeded. > aufs is only used on this system for that one volume, so I tried to > unload it - but it refused! Hence investigating into why. When I mount > the volume after boot manually there is no problem umounting and then > renaming the underlying directory, or unloading aufs - so I know the > issue is being caused by something invalidly holding a reference to the > aufs module, and the reason I'm not raising this as an aufs bug and am As I wrote previously, I don't think the module ref-count is related to your EBUSY problem. Even if you have some other mounted aufs and the ref-count of aufs is 100, you can rename any dir which is not in use. In other words, even if you find out who incremented the aufs ref-count, fix something, succeeded making the ref-count zero and unloading aufs module, you may not be able to rename the dir. It is toally up to "who makes the dir busy." Even if it is aufs, I don't think searching "who increments the aufs ref-count" is effective. J. R. Okajima ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/
