I've now been using unionfs-1.0.12a on both amd64 and x86 in my development tasks and environment and it is very usable. Request for unmask. Reproducible: Always Steps to Reproduce: 1. 2. 3. Gentoo Base System version 1.6.13 Portage 2.0.51.22-r2 (default-linux/amd64/2004.3, gcc-3.4.3, glibc-2.3.5-r0, 2.6.12-gentoo-r6 x86_64) ================================================================= System uname: 2.6.12-gentoo-r6 x86_64 AMD Athlon(tm) 64 Processor 3400+ dev-lang/python: 2.3.5 sys-apps/sandbox: 1.2.10 sys-devel/autoconf: 2.13, 2.59-r6 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.5 sys-devel/binutils: 2.15.92.0.2-r10 sys-devel/libtool: 1.5.18-r1 virtual/os-headers: 2.6.11-r2 ACCEPT_KEYWORDS="amd64" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-pipe -O3 -march=k8" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3/share/config /usr/lib/X11/xkb /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/ /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d" CXXFLAGS="-pipe -O3 -march=k8" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks sandbox sfperms strict" GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/Linux/distributions/gentoo" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="amd64 X aac alsa avi berkdb bitmap-fonts cdr crypt curl dvd encode esd fam flac foomaticdb fortran gif gnome gpm gstreamer gtk gtk2 guile imagemagick imlib ipv6 java jpeg libvisual libwww lzw lzw-tiff mad motif mp3 mpeg multilib ncurses network nls ogg oggvorbis opengl pam pdflib perl png python quicktime readline samba sdl softmmu speex spell sqlite ssl tcltk tcpd tetex theora tiff truetype-fonts type1-fonts usb userlocales vorbis xine xml xml2 xmms xpm xv zlib userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS, LINGUAS
I disagree: unionfs is perfect for read-only usage, but r/w users can incurr in kernel oops, thread race condition and data losses (particularly in concurrent hard link creations or massive deletions) [1]. The main problems lie in the kernel VFS architecture, which originally was not though for deep abstractions (reiserfs4 is another case in which such limitations are revealed). 1.0.13 fixes some of these (==deletions) limitations, but has issues as well. The development is very promising, though, and I think stabilization could come in a couple of releases. genstef: I think this is a wontfix. [1] http://www.fsl.cs.sunysb.edu/pipermail/unionfs/2005-July/thread.html
After posting this request, I found several minor inconsistencies with the unionctl utility along with an occasional Kernel Panic with unioning and deunioning several branches in r/w mode. I agree this is a promising tool but more testing needs to be done.
Won't go stable on amd64...
maybe it will go stable later, just reopne when you consider it stable.