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How to create public mirrors for CentOS

CentOS welcomes new mirror sites.

If you are considering setting up a public mirror site for CentOS please follow these guidelines to make sure that your mirror is consistent with the other mirror sites.

NOTE: To provide fastest access to public mirrors, we have now restricted access (at the IP level) for known public mirrors (see So for your first synchronization, you should use one of the external mirrors providing rsync access. You can find that list here:

As a first step, we'd like you to be subscribed to the following lists (if not already done):

For hard disk space requirements, please refer to the dir_sizes files in the root directory of Please note that at point release times (such as 6.8 -> 6.9) both the old and new releases will be kept on mirrors for a few weeks.

Please email the list when you're all set up with your cron job and your initial sync is completed. We will add you to our list of mirror sites. Please provide all relevant URL's (http/rsync/?) as well as how often you are synchronizing the mirror network. Please include what city/state/country you are in and what your bandwidth (speed) is. Also please give a name and link to the sponsoring organization so we can give proper credit. If the best contact point for your mirror is not the address you are subscribed to the mailing list with, please provide the email address of your preferred contact as well.

It is recommended to check that all your mirror URLs work properly from outside your organization. Firewall problems are surprisingly common. If your mirror has an IPv6 address, you should check IPv4 and IPv6 separately. Both curl and rsync have -4 and -6 options for selecting the protocol.

The following template can be used when sending your mail to the centos-mirror list:

RSYNC: rsync:// (if you provide rsync access)

Sync schedule: Every x hrs
Location: (For US : also mention the State)
Sponsor URL:
IPv4 address to authorize: 
IPv6 address to authorize: 
Email contact: (where we'll send notifications for issues with your mirror)
Mirroring AltArch  : yes/no (and if so, let us know the path, as that will be different as your http/rsync path for CentOS)

We are currently concentrating on HTTP and RSYNC mirrors. If you are setting up a new mirror server from scratch, it might not be worth the effort to set up a FTP daemon and the firewall settings for it. HTTPS is currently not used for mirrors. If you set up HTTPS, please do not redirect HTTP requests to HTTPS. There may be organizations that allow outbound HTTP connections but not HTTPS connections, and any redirects may cause problems for them.

Public mirrors should synchronize 2-4 times per day and this should be run via cron. We highly recommend the use of lock files in your cron script so that you don't spawn multiple connections which is hard on our servers and on your mirror. If you don't know how to do this, please ask the list.

Once your server has been added to the Mirrors DB, and your IP allowed, the best way to keep your mirror updated directly from a machine would be to use the following script (to give you an idea):

rsync -aqzH --delete /path/to/local/mirror/root

There are actually two rsync targets/modules that people can sync from :

EU users may wish to use
US users may wish to use

TIP: If you are using >= 2.6.4 version of rsync, you might want to specify the --delay-updates switch to the above line in your cron job)

NOTE: If you have a data cap which is lower than 15 Tb (depending on region), please don't try to add that machine as a mirror. Please also note: If you are in a country which already has a lot of mirrors (like most western countries do, but also some asian countries), please refrain from trying to add mirrors which have less than 100Mbit/s. If there aren't that many mirrors in your country, we will also accept lower speeds, naturally.

Please alert the CentOS-mirror mailing list if anything about the server changes like location, available bandwidth, frequency of updates, etc.

HowTos/CreatePublicMirrors (last edited 2018-05-14 07:39:24 by AnssiJohansson)