Hello Milan, Milan Zamazal: > 1. Making a new hard link to some files failed with an error. This is a > serious problem that has broken all my `apt-get upgrade' attempts.
Although the details are not clear, hardlink in aufs is working for a long time. Here is an example test output. + sudo mount -o remount,noplink /dev/shm/u + tail -n 3 /proc/mounts /dev/ram1 /dev/shm/ro ext2 ro,relatime,errors=continue 0 0 /dev/ram0 /dev/shm/rw ext3 rw,relatime,errors=continue,barrier=0,data=writeback 0 0 none /dev/shm/u aufs rw,relatime,si=33d9ce2780c03f3f,noplink 0 0 + cat /sys/fs/aufs/si_33d9ce2780c03f3f/br0 /sys/fs/aufs/si_33d9ce2780c03f3f/br1 /dev/shm/rw=rw /dev/shm/ro=ro (now /dev/shm/u = /dev/shm/rw + /dev/shm/ro) + ls -li ../ro/f_src ../ro/f_src_linked ../ro/f_src_linked2 17 -rw-r--r-- 1 jro jro 2 Mar 25 21:50 ../ro/f_src 15 -rw-r--r-- 2 jro jro 2 Mar 25 21:50 ../ro/f_src_linked 15 -rw-r--r-- 2 jro jro 2 Mar 25 21:50 ../ro/f_src_linked2 + ls -li ../rw/f_src ../rw/f_src_linked* ls: cannot access ../rw/f_src: No such file or directory ls: cannot access ../rw/f_src_linked*: No such file or directory + : + ls -li ./f_src ./f_src_linked ./f_src_linked2 22 -rw-r--r-- 1 jro jro 2 Mar 25 21:50 ./f_src 21 -rw-r--r-- 2 jro jro 2 Mar 25 21:50 ./f_src_linked 21 -rw-r--r-- 2 jro jro 2 Mar 25 21:50 ./f_src_linked2 (the f_src* files exist on RO but RW, f_src_linked* are hardlinked) + ln ./f_src ./newfile + ln ./f_src_linked ./newfile_linked (create two new hardlinks) + ls -li f_src f_src_linked f_src_linked2 newfile newfile_linked 22 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 f_src 21 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 f_src_linked 21 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 f_src_linked2 22 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 newfile 21 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 newfile_linked (their inode numbers are expectedly correct, but ...) + sudo mount -o remount /dev/shm/u + ls -li f_src f_src_linked f_src_linked2 newfile newfile_linked 22 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 f_src 21 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 f_src_linked 55 -rw-r--r-- 2 jro jro 2 Mar 25 21:50 f_src_linked2 22 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 newfile 21 -rw-r--r-- 2 jro jro 1 Mar 25 21:50 newfile_linked (after discarding the system cache, the inum of f_src_linked2 is changed. It is simply due to 'noplink' which doesn't maintain the hardlink between branches) > 2. Aubrsync printed error messages about an inaccessible file > occasionally. This looked relatively harmless as the "inaccessible" > files were actually unchanged so nothing bad happened when they were > not copied back. But it makes me worrying about aubrsync/aufs > reliability. > > 3. When I change one of two hard-linked files, `ls -l' still shows > identical information for both of them, although the contents and > sizes of the files are different after the change. No big problem, > but it is confusing. > > 4. On one occasion any attempt to write to a (writable) file failed. > This is a serious problem. > > None of these problems was present in the underlying > /var/lib/vservers.orig directory, I could successfully perform all the > operations on the same files in it. I know aufs in the stable Debian > kernel is not the newest one (according to the kernel changelog it is > 2010-01-25 snapshot). My questions are: I am afraid your aufs module is totally broken. As you wrote, such old version is obsolete and not maintained now. > - Is it possible that I did something wrong? > > - If those are aufs bugs, are they fixed in current aufs or Linux? I'd strongly suggest you to try latest version. J. R. Okajima ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar
