IT 1100 : Introduction to Operating Systems

Chapter 18

Archival and Backup

Compressing files:

• Why?
• How can a file be compressed?

Compression howto

• gzip

• gzip foo.txt
• gunzip foo.txt
• ls -l /etc | gzip > foo.txt.gz

• zcat also allows us to see content of compressed files (whereas cat does not)

Compression howto (again)

• bzip2
  • different compression algorithm
  • bzip2 foo.txt
  • bunzip2 foo.txt

Archival

• Archiving
  • this is different than compression
  • tar is the classic tool for archiving files
    • tar -cvvf foo.tar files_to_tar #creates
    • tar -xvvf foo.tar #extracts
    • tar -cvzf foo.tar files_to_tar #creates and compresses (gzip)

Zip

• Does both archival and compression
• Similar to windows zip program.
  • zip -r foo.zip foo #recursively do this
  • unzip

Rsync

The chapter mentions this and it is important, but we will stick with scp for a while. If you want to know how to use rsync, read the chapter ;-)