[Bug-tar] Re: migration from listed-incremental format 0 to format 2

[John Hein]

John Hein wrote at 12:05 -0600 on Sep  4, 2008:
 > I saw a message where someone else asked a question about this, but
 > there was no response...
 > 
 > http://lists.gnu.org/archive/html/bug-tar/2007-12/msg00002.html
 > 
 > Does anyone have any insight about this?  Is there a migration
 > script for listed-incremental snapshot files?
 > 
 > Is tar > 1.15.90 intended to be able to read older format 0 files
 > (read old, write new)?  Any patches floating around to do this?


I see that the 'Format of the Incremental Snapshot Files' documents
that version 1.20 is supposed to read all formats and write format 2.

In my testing, this seems to be true and restoring seems to work
as expected in a small test.

However, the first tar file created by 1.20 based on a format 0
snapshot file is much larger than expected.  Even if no file changed,
the 'level 1' tar file created is as large as the 'level 0' file.

Is that a bug, or is there no way around it when migrating from format
0 to format 2?