Re: fsimage - no such file

[Matt Wilson <msw@amazon.com>]

On Tue, Jun 19, 2012 at 03:57:33AM -0700, Ian Campbell wrote:
> On Tue, 2012-06-19 at 09:35 +0100, Thanos Makatos wrote:
> > I have the same problem on xen-unstable 54c8c9eaee92+. I think
> > libfsimage comes with xen (in my repo it's under ./tools/libfsimage).
> > I've investigated a bit and found that in my occasion libfsimage tries
> > to access directory /usr/lib64/fs which doesn't exist,
> > whereas /usr/lib/fs does. I linked /usr/lib64/fs to /usr/lib/fs but
> > then I got other problems, don't remember what. I don't know if this
> > has to do with the fact that my dom0 is 64bit (Debian unstable), or
> > that the domU is 64bit (Debian unstable again), or both.
> 
> Aha I'd been puzzling over why people had been seeing this but I'm not! 
> 
> This very likely is to do with Debian and Ubuntu's transition to
> "multiarch" which has necessitated removing the old compatibility
> symlink /usr/lib64 -> /usr/lib.
> 
> lib64 is a RPMism which doesn't really apply to Debian and derivatives
> and therefore you need to tweak your Xen config before building. I use
> the following local configuration patch (I should probably do the
> equivalent in .config):

lib64 isn't an RPMism, its a Filesystem Hiarchary Standardism [1].

Pretty much every distribution but Debian (and derivatives) adopted
lib64 for all platforms where running 32-bit binaries was common place
(read: all platforms but Alpha and Itanium).

Matt Taggart proposed multiarch for Debian in 2004 (where Red Hat and
SUSE already had support for running a mix of 32-bit and 64-bit
applications on one system), which is captured in the Debian wiki [2].
Ubuntu added support for co-installing 32-bit and 64-bit software in
11.04 [3].

I'm a bit surprised that Debian and Ubuntu can't continue to have a
symlink for lib64 that points at lib/x86_64-linux-gnu. No matter since
I suppose the correct fix is to install the plugins in /usr/lib/$target/fs 
and define FSIMAGE_FSDIR to point there when building libfsimage on
systems that implement multiarch.

Matt

[1] http://www.pathname.com/fhs/
[2] http://wiki.debian.org/Multiarch/TheCaseForMultiarch
[3] https://wiki.ubuntu.com/MultiarchSpec