[Dirvish] Macs and UFS and Rsync and Dirvish

Keith Lofstrom keithl at kl-ic.com
Fri Oct 27 06:58:47 PDT 2006

There have been questions about backing up Mac OSX Tiger 10.4
file systems with dirvish and rsync.  This is complicated by
the way UFS works.  It is probably not un-solvable, but to date
it has not been solved, and solutions will require modifications
to rsync and maybe to OSX.

For more information, watch the mailing lists for rsync:


And also the Mac OS-X server mailing list:


There is a discussion of backup going on right now on the Mac list;
changes to 10.4 are breaking many common Mac backup tools, not just

When Wayne Davidson's mainline rsync is modified to handle the
intricacies of 10.4 UFS+, we may need to make modifications to
dirvish to handle those modifications.  It may be possible to do
backups on UFS+ with the existing version of rsync and some extra
cleverness, but at this time nobody on either of the above lists
has contributed a solution. 

Sometimes the operating system does not even permit a complete 
backup solution - rsync has this problem with Windows XP, though 
some clever people have developed workarounds.  Even on Linux, the
way the OS handles symbolic links does not permit dates and times
to be restored with rsync.  Many of these problems can only be
fixed by adding to the operating system, and that will be difficult
for proprietary operating systems.

Dirvish is a wrapper around rsync, which in turn depends on the
API provided by the operating system underneath.  If rsync or
the API are inadequate, there is not much we can do to dirvish
to work around that.  I would really like to see solutions, I
want to back up a 10.4 system too.  Not yet.  :-(


Keith Lofstrom          keithl at keithl.com         Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs

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