If a file in an overlay merged directory is being periodically written to: tail -f will not show additions if given the file in the location of the merged directory; but tail -f will show additions if given the file in the location of the lower directory. On a fresh Fedora 22 (kernel 4.0.4-303.fc22) (netinstaller, so most up to date packages, "Minimal Install") or a fresh Arch Linux (kernel 4.0.5-1-ARCH), running through VMWare Workstation 11.1, I experience the following bug. 1. mkdir lowerdir upperdir merged workdir 2. sudo modprobe overlay 3. sudo mount -t overlay -o lowerdir=/home/username/lowerdir,upperdir=/home/username/upperdir,workdir=/home/username/workdir overlay /home/username/merged 4. cd merged 5. while true; do echo hello >> while.loop.out; sleep 1; done & 6. ls -la while.loop.out, wait a few seconds, run again, wait, run again. (observe while.loop.out is growing.) 7. tail -f while.loop.out. observe the most recent 10 lines, and no updates. 8. tail -f ../upperdir/while.loop.out. observe while.loop.out's updates. 9. cleanup. fg, then CTRL+C I'm betting this is a kernel/overlay filesystem bug rather than a tail bug. Tail should not know or care whether it's being given a file in an overlay filesystem. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
