Hi, we're looking to extend the geographical coverage of CentOS AltArch mirrors a bit. For those who don't know, the Alternative Architecture SIG produces CentOS 7 for all kinds of odd architectures such as aarch64, armhfp, i386, power9, ppc64 and ppc64le.
We have a separate list of mirrors providing AltArch content at https://www.centos.org/download/altarch-mirrors/ and if you have a look at that list, you will notice that there are several mirrors from Europe and U.S., but less from other regions.
We're currently in the process of shifting AltArch-related traffic from mirror.centos.org to external mirrors. Most of those mirror.centos.org nodes double as msync nodes, and by directing users to use external mirrors instead of mirror.c.o, more bandwidth would be available for syncing external mirrors. In addition to the saved bandwidth, many of the external mirrors have much more bandwidth than msync.c.o nodes, so the end users will also see a benefit.
If the existing AltArch mirrors have a look at their traffic stats, they will probably notice that there hasn't been much AltArch traffic. That will see a slight increase soon, though. We will soon push out updated centos-release packages for AltArch that will use mirrorlist.c.o to find a nearby external mirror, instead of the currently configured mirror.centos.org. The old mirror crawler only checked main architecture repos (and only a subset of those), but the current mirror crawler will check main architectures and AltArch architectures, and all the repositories that are active.
Some AltArch .iso download links have also been changed to point to isoredirect.c.o, which has a newly added capacity to redirect AltArch .iso image requests to external mirrors. The remaining AltArch .iso redirects to external mirrors will be done prior to CentOS 7.6.18xx release.
That said, I don't expect AltArch to generate significant additional traffic compared to the main architectures. My primary concern here is the geographical coverage, ie. the number of countries represented. Let's say that it'd be nice if there were mirrors from a handful of countries from each continent.
If there isn't yet an AltArch mirror in your country and you think your mirror could close a "gap", please consider mirroring AltArch as well. At the moment AltArch consumes around 100 GB of disk space. Please note that when CentOS 7.6.18xx gets released, both 7.5.1804 and 7.6.18xx will be kept on mirrors for a while, thus temporarily doubling the disk space required.
Another technical point is that if you start mirroring AltArch, the content must be available in a different directory (and thus at a different URL) than the main content. One common convention is to have directories "centos" and "centos-altarch". You will also need to invoke rsync twice; first for the main content (as before) and then for the AltArch content at rsync://msync.centos.org/altarch/
Although all current CentOS mirrors can already access the above msync.c.o module for AltArch, it would be nice if you could do your initial rsync from some other external mirrors listed on https://www.centos.org/download/altarch-mirrors/ , even if the nearest external mirror providing AltArch over rsync isn't exactly nearby. Once you have done an initial sync from an external mirror, you can switch to doing incremental syncs from rsync://msync.centos.org/altarch/
Once you are done, please provide the http/https/rsync URLs to your mirrored AltArch content so those could be added to the list.
Thanks for reading this far, and thanks for all the bandwidth!