2. Requirements for FreeBSD mirrors

2.1. Disk Space

Disk space is one of the most important requirements. Depending on the set of releases, architectures, and degree of completeness you want to mirror, a huge amount of disk space may be consumed. Also keep in mind that official mirrors are probably required to be complete. The web pages should always be mirrored completely. Also note that the numbers stated here are reflecting the current state (at 9.3-RELEASE/10.0-RELEASE). Further development and releases will only increase the required amount. Also make sure to keep some (ca. 10-20%) extra space around just to be sure. Here are some approximate figures:

  • Full FTP Distribution: 1.4 TB

  • CTM deltas: 10 GB

  • Web pages: 1GB

The current disk usage of FTP Distribution can be found at ftp://ftp.FreeBSD.org/pub/FreeBSD/dir.sizes.

2.2. Network Connection/Bandwidth

Of course, you need to be connected to the Internet. The required bandwidth depends on your intended use of the mirror. If you just want to mirror some parts of FreeBSD for local use at your site/intranet, the demand may be much smaller than if you want to make the files publicly available. If you intend to become an official mirror, the bandwidth required will be even higher. We can only give rough estimates here:

  • Local site, no public access: basically no minimum, but < 2 Mbps could make syncing too slow.

  • Unofficial public site: 34 Mbps is probably a good start.

  • Official site: > 100 Mbps is recommended, and your host should be connected as close as possible to your border router.

2.3. System Requirements, CPU, RAM

One thing this depends on the expected number of clients, which is determined by the server's policy. It is also affected by the types of services you want to offer. Plain FTP or HTTP services may not require a huge amount of resources. Watch out if you provide rsync. This can have a huge impact on CPU and memory requirements as it is considered a memory hog. The following are just examples to give you a very rough hint.

For a moderately visited site that offers rsync, you might consider a current CPU with around 800MHz - 1 GHz, and at least 512MB RAM. This is probably the minimum you want for an official site.

For a frequently used site you definitely need more RAM (consider 2GB as a good start) and possibly more CPU, which could also mean that you need to go for a SMP system.

You also want to consider a fast disk subsystem. Operations on the SVN repository require a fast disk subsystem (RAID is highly advised). A SCSI controller that has a cache of its own can also speed up things since most of these services incur a large number of small modifications to the disk.

2.4. Services to offer

Every mirror site is required to have a set of core services available. In addition to these required services, there are a number of optional services that server administrators may choose to offer. This section explains which services you can provide and how to go about implementing them.

2.4.1. FTP (required for FTP fileset)

This is one of the most basic services, and it is required for each mirror offering public FTP distributions. FTP access must be anonymous, and no upload/download ratios are allowed (a ridiculous thing anyway). Upload capability is not required (and must never be allowed for the FreeBSD file space). Also the FreeBSD archive should be available under the path /pub/FreeBSD.

There is a lot of software available which can be set up to allow anonymous FTP (in alphabetical order).

  • /usr/libexec/ftpd: FreeBSD's own ftpd can be used. Be sure to read ftpd(8).

  • ftp/ncftpd: A commercial package, free for educational use.

  • ftp/oftpd: An ftpd designed with security as a main focus.

  • ftp/proftpd: A modular and very flexible ftpd.

  • ftp/pure-ftpd: Another ftpd developed with security in mind.

  • ftp/twoftpd: As above.

  • ftp/vsftpd: The very secure ftpd.

FreeBSD's ftpd, proftpd and maybe ncftpd are among the most commonly used FTPds. The others do not have a large userbase among mirror sites. One thing to consider is that you may need flexibility in limiting how many simultaneous connections are allowed, thus limiting how much network bandwidth and system resources are consumed.

2.4.2. Rsync (optional for FTP fileset)

Rsync is often offered for access to the contents of the FTP area of FreeBSD, so other mirror sites can use your system as their source. The protocol is different from FTP in many ways. It is much more bandwidth friendly, as only differences between files are transferred instead of whole files when they change. Rsync does require a significant amount of memory for each instance. The size depends on the size of the synced module in terms of the number of directories and files. Rsync can use rsh and ssh (now default) as a transport, or use its own protocol for stand-alone access (this is the preferred method for public rsync servers). Authentication, connection limits, and other restrictions may be applied. There is just one software package available:

2.4.3. HTTP (required for web pages, optional for FTP fileset)

If you want to offer the FreeBSD web pages, you will need to install a web server. You may optionally offer the FTP fileset via HTTP. The choice of web server software is left up to the mirror administrator. Some of the most popular choices are:

  • www/apache22: Apache is the most widely deployed web server on the Internet. It is used extensively by the FreeBSD Project.

  • www/thttpd: If you are going to be serving a large amount of static content you may find that using an application such as thttpd is more efficient than Apache. It is optimized for excellent performance on FreeBSD.

  • www/boa: Boa is another alternative to thttpd and Apache. It should provide considerably better performance than Apache for purely static content. It does not, at the time of this writing, contain the same set of optimizations for FreeBSD that are found in thttpd.

All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/

Questions that are not answered by the documentation may be sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.