Re: Announcing xorriso-0.4.0

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Joerg Schilling wrote:
> Did you verify correct behavior of the hard link support ?

Within libisofs and xorriso it behaved plausible
and stable in my tests.

The Linux kernels of recent years re-compute the
inode number from the ECMA-119 directory record's
byte address but read struct stat.st_ino from the
Rock Ridge PX entry of the directory record.
So one will see the intended link count but not
the intended inode numbers in a mounted isofs.
This will prevent cp -a from recognizing the
hard link relations.


But as with ACL and xattr, xorriso is able to
restore what it recorded.

After adding reliable recording of hard link
relations, i now deem xorriso to provide a very
high backup fidelity.

Its basic archive format is documented in
two layers: as ECMA-119 (can be read by DOS)
and as RRIP-1.10 resp. RRIP-1.12 (can be
read by X/Open systems).
Its extension format for ACL and xattr is
documented as
  http://libburnia-project.org/wiki/AAIP
The data format for zisofs compressed file
contend is documented as
  http://libburnia-project.org/wiki/zisofs
(scroll down 50 lines for reaching the specs.
zisofs was invented and first implemented
by H.Peter Anvin in zisofs-tools + mkisofs.
Recent Linux kernels read it transparently.)

So there is a wide range of existing partial
readers for xorriso's format, there is xorriso
as complete reader, and there are the specs
for those who need elementary access on byte
level.
This all with random access. No waiting 20
minutes until a few files are extracted from
a 20 GB archive on Blu-Ray.
And with incremental backup on multi-session
media and on overwriteable media.


> Why do ou try to pretend that there is libfind support

Do i ?

> without supporting a real find(1) command line?

xorriso's option -find is inspired by program
find. It implements a subset of its gestures and
it adds specific extensions.

Similarly xorriso has options like -ls, -du,
-mkdir, -rm, -mv, -chown, -chmod which serve
the typical purpose of their paragons while
not being full emulations.

>From man xorriso: "xorriso is not a shell".


Have a nice day :)

Thomas