What is wrong with this?
tar --diff --gunzip --file=/media/disk/filename.tgz
This is GNU tar 1.23 on Ubuntu. The complaint is gzip:stdin:input/output error
.
The following just hangs and there is no apparent disk seek activity.
tar --diff fz /media/disk/filename.tgz
tar --compare fz /media/disk/filename.tgz
tar -d vfz /media/disk/filename.tgz