1. Create some realistic data partition. In my case it's FreeBSD 10.2 base system (binaries and data), no sources and 230 packages, full list is here:
http://bit.ly/1QMw1D0
2. Make 4 versions of the compressed image with new mkuzip(8):
# mkuzip -o outfile.zcomp.nodedup.uzip infile
# mkuzip -Z -o outfile.nozcomp.nodedup.uzip infile
# mkuzip -d -o outfile.zcomp.dedup.uzip infile
# mkuzip -Zd -o outfile.nozcomp.dedup.uzip infile
3. Attach all 4
# mdconfig -a -f outfile.zcomp.nodedup.uzip
md0
# mdconfig -a -f outfile.nozcomp.nodedup.uzip
md1
# mdconfig -a -f outfile.zcomp.dedup.uzip
md2
# mdconfig -a -f outfile.nozcomp.dedup.uzip
md3
4. Try reading data with some off block size and see if it matches:
# dd if=infile bs=260608 status=none | md5
# dd if=/dev/md0.uzip bs=260608 status=none | md5
# dd if=/dev/md1.uzip bs=260608 status=none | md5
# dd if=/dev/md2.uzip bs=260608 status=none | md5
# dd if=/dev/md3.uzip bs=260608 status=none | md5
5. Change block size, see if you can break it. fsck the resulting device node, try to mount/chroot in there and run some I/O tests.