diff --git a/handbook/synching.sgml b/handbook/synching.sgml index 4d96c16cc1..d9eb695ec8 100644 --- a/handbook/synching.sgml +++ b/handbook/synching.sgml @@ -1,68 +1,68 @@ - + Synchronizing source trees over the Internet

Contributed by &a.jkh;.

There are various ways of using an Internet (or email) connection to stay up-to-date with any given area of the FreeBSD project sources, or all areas, depending on what interests you. The primary services we offer are CTM, SUP and CVSup (new).

It's been suggested by some that CTM obsoletes SUP. This isn't quite true, in fact, because each tool was originally designed to serve a different constituency and, although they have both undergone significant improvement since first going into service, they take fundamentally different approaches in trying to solve the source synchronization problem. SUP was originally designed to support those who had dedicated (or at least fast) Internet connections whereas CTM was originally aimed at supporting those who's access was limited to email only.

SUP (Software Update Protocol) is a system that tracks a local copy of the FreeBSD sources on your local disk and, using configuration files the user sets up, makes requests over the network to fetch and update any files which have changed on the FreeBSD master archive.

CTM, on the other hand, does not interactively compare the sources you have with those on the master archive. Instead, a script which identifies changes in files since its previous run is executed several times a day on the master archive, any detected changes being compressed, stamped with a sequence-number and encoded for transmission over email (printable ASCII only). Once received, these "CTM deltas" can then be handed to the ctm_rmail(1) utility which will automatically decode, verify and apply the changes to the user's copy of the sources. This process is far more efficient than SUP, and places less strain on our server resources since it's a push rather than a pull model.

There are other trade-offs, of course. With SUP, you can also inadvertently wipe out portions of your archive and SUP will detect and rebuild the damaged portions for you. CTM won't do this, and if you wipe some portion of your source tree out (and don't have it backed up) then you will have to start from scratch (from the most recent CVS "base delta") and rebuild it all.

More recently, the waters have been muddied even more by the introduction of the CVSup utility, a highly efficient replacement for SUP which also offers access to any branch of FreeBSD development from a single CVS repository (which, in turn, can also be transferred non-destructively with CVSup - any local developer work on -independant branches is preserved). It overcomes many of SUP's shortcomings +independent branches is preserved). It overcomes many of SUP's shortcomings and may be from our development server, where additional documentation is also provided. Both the CVSup client and server are compatible with the sup and supfilesrv distribution file formats. For more information on SUP and CTM, please see one of the following sections: ⊃ &ctm;