刚发现 Ultimate Boot CD v3.3 中用CDShell加载的镜象文件为igz格式。
一直未用过CDShell，未知igz格式是用什么做出来的呢？如何编辑呢？
原来官方网站有说明：
How do I edit files with the .igz extension? How do I create my own .igz files?
[Contributed by Charles Appel] .igz files are img files compressed with GZIP.
To edit a .igz files, convert it back to the .img format:
Rename memtestp.igz to memtestp.img.gz
Uncompress using gzip -d memtestp.img.gz
Make whatever changes you want to memtestp.img
Recompress using gzip -9 memtestp.img
Rename memtestp.img.gz to memtestp.igz
To create your own .igz files:
Compress image using gzip -9 image.img
Rename image.img.gz to image.igz