Is this a dumb idea?

I am zipping a image file on a USB Hard Drive, so is this going to work?
(I do not have enough space for the full file on a real hard drive)

and how long will it take?
or
can anybody suggest me a faster way to get rid of all the zeros in the image?

If you are trying to image a drive, you might want to consider Partimage.

Is it going to work? Do you mean, will the image file ultimately finish gzipping onto the drive? Probably, assuming you have enough space and time (where time decreases the faster your CPU is). How long, again, depends on the speed of your CPU almost exclusively. The first bottleneck will probably be the drive, next the USB bus, and finally the CPU speed, assuming you are using a relatively new system.

A faster way, I guess it really depends on what you ultimately need. It may be "faster" to rsync the file, ftp the file or remote mount the disc and simply cp the file; all depends on the goal.

-Chad

thanks guys

all i want to do is save the factory state of my laptop, then zip it so that it won't take up much space

partimage looks good