Overview
Compressing directories and files on your web server into a .zip, .tar.gz, or .tar.bz2 archive makes them smaller and easier to download to your local computer.
Prerequisites
This article assumes you have created a shell user and are able to log into your server via SSH.
Compressing directories
This section shows how to compress a directory to a .zip, .tar.gz, or .tar.bz file.
How do I compress a directory to a .zip file?
This example uses the zip command to compress a directory named example.com into a new file named example.com.zip. The original directory remains untouched.
[server]$ zip -r example.com.zip example.com
You can use the maximum compression setting (-9), which attempts to compress all files. However, this may be slower:
[server]$ zip -9 -r example.com.zip example.com
How do I compress a directory to a .tar.gz file?
This example uses the tar command to compress a directory named images to a file named image_backup.tar.gz. The original directory continues to exist.
[server]$ tar zcvf image_backup.tar.gz images
How do I compress a directory to a .tar.bz2 file?
This tar command compresses a directory named images to a file named image_backup.tar.bz2. The original directory continues to exist.
[server]$ tar cjvf image_backup.tar.bz2 images
What command compresses a directory the most?
The examples below show how much a WordPress site is compressed using the different compression options. First, check the size of the WordPress directory. The original size is 82M.
[server]$ du -sh example.com 82M example.com
The following are the results of the different compression methods.
[server]$ du -sh example.com.zip 30M example.com.zip
[server]$ du -sh example.com.tar.gz 27M example.com.tar.gz
[server]$ du -sh example.com.tar.bz2 24M example.com.tar.bz2
Overall, tar.bz2 compresses the most.
How do I confirm my directory has been compressed?
Once you run the commands above, check to confirm the directory has been compressed. You can do this using du -sh for both the old and new directories.
[server]$ du -sh example.com.zip 30M example.com_backup
[server]$ du -sh example.com 82M example.com
You can see above that the compressed backup is smaller in size than the original directory.
Compressing files
The examples below use gzip to compress a file.
How do I compress and rename a file?
This command compresses a file named test.log while renaming it to test.log.gz. Please note that because the original file was renamed, it no longer exists.
[server]$ gzip test.log
How do I copy and compress a file?
If you still need the test.log file to exist, run the following instead. This uses the -c flag to create a gzipped copy of the file:
[server]$ gzip -c test.log > test.log.gz