rootninja

Instead of storing whole dd images, even if they’re just backups of small partitions, you can save space and bandwidth by piping dd into a compression utility like gzip.

# dd if=/dev/sda3 | gzip -c > sda3-home.dd.gz
11597258+0 records in
11597258+0 records out
5937796096 bytes (5.9 GB) copied, 10.1747 s, 584 MB/s

The partition was about six gigabytes, but compressed it’s a lot smaller.

# ls -lh sda3-home.dd.gz
total 3.8G
-rw-r–r– 1 root root 3.8G Feb 19 06:47 sda3-home.dd.gz

I can get a checksum of the image to verify it is what I expect it to be, by using sha1sum.

# gzip -cd sda3-home.dd.gz | sha1sum
f0fe480abc1489dfac379b68f6095a7fd6c0c959 -