Compression

Compression Method
gzip  (1K corrupted will cause whole file crashed)
bzip2 (better; 1K corruped only cause 900K crashed)

bzip2 (.bz2)
Install
aptitude intsall bzip2

Compress
bzip2 /xxx
bzip2 -k /xxx (k: keep the old file)

Decompress
bzip2 -d /xxx.bz2
bzip2 -dk /xxx.bz2 (k: keep the old file)

gzip (.gz)
Install
aptitude intsall gzip

Compress
gzip /xxx

Decompress
gzip -d /xxx

tar (.tar .tar.bz2)
Compress
tar -cf /xxx.tar /xxx
tar -cjf /xxx.tar.bz2 /xxx
tar -czf /xxx.tar.gz /xxx

Decompress
tar -xf /xxx.tar
tar -xjf /xxx.tar.bz2
tar -xzf /xxx.tar.gz