The -z option in Rsync is used to enable compression, which can optimize the file transfer process by transferring less data over the network. It is particularly useful when transferring large files over slow network connections, as it reduces the amount of data that needs to be sent, potentially speeding up the transfer time.
Rsync is a powerful file copying tool used for synchronizing files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important aspect of Rsync is that it’s capable of preserving various file attributes such as timestamps, permissions, user & group ownership, and symbolic links.
According to the Rsync Man Page from Samba.org, the -z, —compress option “compresses the file data as it is sent to the destination machine, which reduces the amount of data being transmitted — something that is useful over slow connections”.
Here’s an example of how to use the -z option in Rsync:
rsync -az user@source:/dir/to/copy /destination/dir
In this example, -a stands for ‘archive’ which preserves the files’ attributes like permissions and timestamps, and -z enables compression.
However, it should be noted that while the -z option is quite beneficial for slower network connections and larger files, it can add an overhead of CPU usage for the compression and decompression process. As per the guidelines provided by Techarp.com, it is recommended not to use the -z option when dealing with faster network connections or when copying files within the same machine as the time saved in data transfer can be offset by the time spent on compression and decompression.
In summary, the -z or —compress option in Rsync is for enabling the compression of data as it is sent to the destination machine. Its usage can result in reduced amount of data transmission hence faster data transfer, particularly where network connections are slow. However, the decision to use -z should take into account both the speed of the network connection and the size and nature of the files being transferred.
Sources:
1. “Rsync (Remote Sync): 10 Practical Examples of Rsync Command in Linux” – Tecmint. https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/
2. “Rsync Man Page” – Samba. https://www.samba.org/ftp/rsync/rsync.html
3. “The Beginner’s – Guide to Rsync (Remote Sync)” – Techarp. https://techarp.com/resource/beginners-guide-rsync-script-linux/
