How to Use the Command 'rankmirrors' (with examples)

The rankmirrors command is a useful utility for Arch Linux users who want to optimize their package fetching process by ranking a list of Pacman mirrors. The command evaluates the speed and responsiveness of different mirror servers. By prioritizing faster servers, users can enhance their system’s package download performance. The command writes a new mirror list to stdout, allowing users to easily update their system’s configuration.

Use case 1: Rank a Mirror List

Code:

rankmirrors /etc/pacman.d/mirrorlist

Motivation: In the world of Linux systems, updates and installations are a frequent task. Pacman, the package manager for Arch Linux, utilizes mirror servers from around the globe to provide these updates and packages. By default, Pacman does not prioritize mirrors. So, for improved download speeds, it is crucial to rank and use the fastest available mirrors. This use case demonstrates how to rank the available mirrors to ensure optimal performance and reliability.

Explanation:

• /etc/pacman.d/mirrorlist: This is the default mirror list file used by Pacman on Arch Linux systems. The command evaluates this file to determine the rank of each server based on speed and responsiveness.

Example Output:

Server = http://mirror1.example.com$repo/os/$arch
Server = http://mirror2.example.com$repo/os/$arch
Server = http://mirror3.example.com$repo/os/$arch

Use case 2: Output Only a Given Number of the Top Ranking Servers

Code:

rankmirrors -n 5 /etc/pacman.d/mirrorlist

Motivation: In certain situations, users may want to limit the number of top-performing mirrors used by their system. This could be due to preferences for specific geographical servers or to maintain a small, quick-to-update mirror list. This use case shows how to filter and retrieve only a specified number of top-performing mirrors.

Explanation:

• -n 5: The -n flag specifies that only the top five mirrors will be output from the ranking process. This helps to narrow down and focus on a limited set of reliable servers.
• /etc/pacman.d/mirrorlist: The mirror list file is still the source of the command to read and rank from.

Example Output:

Server = http://topmirror1.example.com$repo/os/$arch
Server = http://topmirror2.example.com$repo/os/$arch
Server = http://topmirror3.example.com$repo/os/$arch
Server = http://topmirror4.example.com$repo/os/$arch
Server = http://topmirror5.example.com$repo/os/$arch

Use case 3: Be Verbose when Generating the Mirror List

Code:

rankmirrors -v /etc/pacman.d/mirrorlist

Motivation: During the process of ranking, detailed information can be highly useful for troubleshooting or understanding the behavior of the mirrors being used. Verbose mode provides insights into each step being taken by rankmirrors, enabling users to make informed decisions or adjustments based on this information.

Explanation:

• -v: This flag activates verbose mode, which provides detailed feedback and progress information during the execution of the command. It’s useful for understanding what happens behind the scenes.
• /etc/pacman.d/mirrorlist: Again, this is the source of mirror information to be assessed and ranked.

Example Output:

Parsing mirrors: /etc/pacman.d/mirrorlist...
Testing mirror: http://mirror1.example.com ... Success, response time: 50 ms
Testing mirror: http://mirror2.example.com ... Success, response time: 80 ms
All mirrors ranked!

Use case 4: Test Only a Specific URL

Code:

rankmirrors --url http://mirror.example.com

Motivation: A system administrator or user might want to test the performance of a specific mirror without altering the entire mirror list. This is particularly useful when considering new mirrors or verifying the speed of a preferred mirror. This use case illustrates how to focus the ranking process on a single URL.

Explanation:

• --url http://mirror.example.com: This option specifies that only the provided URL is to be tested for speed and connectivity. It bypasses the default mirror list file, allowing for isolated assessment.

Example Output:

Testing single URL: http://mirror.example.com ...
Success, response time: 45 ms

Use case 5: Output Only the Response Times Instead of a Full Mirror List

Code:

rankmirrors --times /etc/pacman.d/mirrorlist

Motivation: Sometimes, users may want to know just the response times of each mirror to better understand their system’s network performance regarding specific mirrors. This is helpful when needing detailed performance metrics without making changes to their mirror list.

Explanation:

• --times: This option instructs rankmirrors to output solely the response times for each mirror. Instead of generating a new ranked list, it provides a simple performance measurement.
• /etc/pacman.d/mirrorlist: As usual, this is the list from which mirror information is read.

Example Output:

http://mirror1.example.com responded in 50 ms
http://mirror2.example.com responded in 70 ms
http://mirror3.example.com responded in 80 ms

Conclusion

The rankmirrors command is an invaluable tool for optimizing the use of mirror servers on an Arch Linux setup. By allowing users to rank mirrors based on performance, limit the number of mirrors, and obtain detailed information, it offers flexibility and control that can significantly enhance package download and update speeds. Whether you’re a system administrator managing multiple machines or a single user looking to improve system efficiency, understanding and utilizing rankmirrors can provide marked improvements.