How do I save a disk image of my laptop hard drive?

[Dale Farnsworth]

In article <200704061031.35239.mark at phillipsmarketing.biz> you write:
> Could someone help me verify that the entire hard drive was copied?
> 
> This is the message at the end of the copying:
> 
> 29302560+0 records in
> 29302560+0 records out
> 30005821440 bytes (30 GB) copied, 6036.72 seconds, 5.0 MB/s
> 16656403+379 records in
> 16656403+379 records out
> 17056356977 bytes (17 GB) copied, 6036.63 seconds, 2.8 MB/s
> 
> The resulting image is only 16GB for a 30 GB drive. I know I used compression, 
> but I just want to make sure it worked. It does say 30Gb copied. 

That looks right.  50% compression by gzip seems reasonable.

> Just looking for some comfort before I wipe out this drive!

If you're paranoid, you could do something like "sum /dev/hda" on the
laptop and then "gunzip <backupfile | sum" on the system containing
the backup file.  The checksums reported by both commands should be
identical.  NOTE: This will not work if you have modified /dev/hda
in *any* way (including mounting one of the partitions) between the
backup and running sum.

-Dale Farnsworth