Using sparse files for the test configurations had atleast three
significant advantages.
1) Actually test sparse files to ensure they work.
2) Drastically reduce required disk space for the regression test
suite. This turns out to be fairly important when running the
test suite in a virtualized environment.
3) Significantly speed of the test suite. Run time of zconfig.sh
dropped from 2m:56s to 1m:00s on my test system, zpios-sanity.sh
nows runs in only 0m:26s.
5545adeadf