I moved from Linux VServer to Linux containers and looked for an equivalent of the VServer hashify facility. I tried to run aufs as a copy-on-write file system over the tree of interlinked files, mounting it with `br:/var/lib/vservers.branch:/var/lib/vservers.orig,noplink' (using noplink in order to break the links on file changes). The system is Debian 6.0 amd64 ext3.
I had to abandon aufs very soon because of the following problems: 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. 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: - Is it possible that I did something wrong? - If those are aufs bugs, are they fixed in current aufs or Linux? - If aufs is really unusable for the purpose, do you know about any reasonable way to emulate hashify on Linux containers? ------------------------------------------------------------------------------ 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
