Challenge: dump | restore

[Edward Ned Harvey]

This runs for a few minutes, and results in a broken pipe.  After which, at
least some fragments of the filesystem have been restored on the destination
filesystem.  At least some directories.

cd /mnt/newFS

dump -0af - /dev/someVG/sourceFS | restore -rf -

 

This works fine.

cd ~

dump -0af somefile /dev/someVG/sourceFS 

cd /mnt/newFS

restore -rf ~/newFS

 

Source and destination filesystems are ext3, 194G and 857G.  Destination
filesystem is created with simply default mkfs.ext3.  There are only approx.
200M used in the source filesystem, of which, there's no particularly huge
directory or number of inodes or anything unusual...  I forced the fsck, and
it came back clean.

 

My only guess is that there seems to be something wrong with the pipe.
Like, it's not streaming the bits properly or something.  Is it possible to
overflow a pipe or something?  I can't think of any good explanation for
this weird behavior.  What could cause a pipe to break, aside from the
receiving process terminating unexpectedly?