+
+... get the current OpenBSD source- or cvs-tree daily -via email
+-
+Ctm uses very low bandwith for distributing the changes to the +tree, and compresses them using gzip -9. -
ctm is a system which was designed by Poul-Henning Kamp for making all -the changes to the FreeBSD source- and cvs-tree (and some other trees - -like the FreeBSD ports-tree) available on a daily (or multiple time per -day) basis by email. this is a very good way to stay up to date with the -current source- or cvs-tree if you have a bad internet connection - for -instance via modem.
+ctm uses only very low bandwith for distributing the changes to the -tree - and it compresses these differences using gzip -9.
++The basic idea of ctm is that you subscribe to a special mailing list +for a particular source tree. Each day you receive an email message +containing all the changes to that tree during that period. +One set of differences is called a "delta". -
+You begin with a base set against which later deltas are patched. +To begin using ctm you must grab the latest base set and all deltas +after that; once you have processed those you can process later +deltas you receive on the mailing list. -
the basic idea of ctm is - that you subscribe to a special mailinglist -to get the daily changes of the OpenBSD source- or cvs-tree and then you'll -get a mail each day containing all the changes to the tree (maybe we increase -the number of ctm files sent per day in the future) - one such set of differences -is called a "delta".
++Bases are generated once approximate each 100 relative deltas, so you never +have to grab more than 100 deltas to catch up. -
if you received your first delta - you have to download all the delta's -until the first delta you received by email - this always starts with a -big - so called "base delta" - which contains the full source -tree you start with. starting from this big one all other deltas only contain -the changes to the tree of the day of the delta generation. to avoid that -you have to get the base delta and then some hundred relative deltas a -new base delta is generated as a startpoint each 100 relative delta's - -so that you always have to get less than hundred relative deltas for starting -ctm :-)
++As mentioned above, the base set contains a full source tree in TAR format, +and is thus quite large. You must obtain the base set and all relative +deltas up to present via ftp from the site listed below. Sizes are: -
as said above the base delta contains the full source- or cvs-tree so -it is really big - you'll have to get it via ftp from the site below. here -are the sizes of the current base deltas: ~ 45 mbyte for OpenBSD-src.0001.gz -- the base delta for the source-tree ~ 55 mbyte for OpenBSD-cvs.0001.gz -- the base delta for the cvs-tree and the size of the relative deltas vary -from ~ 10 kbyte to ~ 100 kbyte usually and sometimes they are some (1,2 -or 3) mbytes - but they are always split into 100 kbyte mails which will -automatically assembled from the ctm-programs - the bigger sizes come from -bigger changes in the source- or cvs-tree (update of the binutils, import -of perl etc.)
++Larger ctm updates are rare, though, usually occuring only after a major +import of something like binutils, perl, etc. -
ctm is very simple to use:
+echo subscribe OpenBSD-src | mail majordomo@OpenBSD.org for the -source-tree
-+ There are several mailing lists related to ctm. There is a list for + updates to the source tree, a list for updates to the cvs tree, a list + for announcements where I'll post important announcements to ctm users, + and a list for seeing log messages from the ctm delta generator runs. +
+ The following commands will subscribe you to the appropriate lists:
+
+For the source tree:
+ echo subscribe OpenBSD-src | mail majordomo@OpenBSD.org
+For the cvs tree:
+ echo subscribe OpenBSD-cvs | mail majordomo@OpenBSD.org
+For the announce list:
+ echo subscribe ctm-announce | mail majordomo@OpenBSD.org
+For the ctm log list:
+ echo subscribe ctm-log | mail majordomo@OpenBSD.org
+
-
or
+echo subscribe OpenBSD-cvs | mail majordomo@OpenBSD.org for the -cvs-tree
--
you should also subscribe to
+echo subscribe ctm-announce | mail majordomo@OpenBSD.org
-on this list i'll post announcements for users of ctm and there is also -a list for somekind of a log of the ctm delta generation - so you can see -what is all in the ctm delta and if the assembling of it succeeded - you -should really subscribe to this list if you use ctm using
+where splitted is the directory in which you placed the files you +grabbed. -echo subscribe ctm-log | mail majordomo@OpenBSD.org
-+It is no longer necessary to keep these files around, if you're sure +you've got a complete tree. However, be sure to note the number of the +base, before continuing. -
+You now need to grab the deltas which have been generated since the base
+was generated. Go to the ftp site below in the subdirectory src or
+cvs and grab every file whose number is
+The address of the base and deltas is: -
ctm_rmail -p. -d. -b. the_mail_folder_containing_the_ctm_delta_mail
-after that you should have the bare ctm delta there (something like -OpenBSD-cvs.0015.gz or so)
++
-
+It will take some time to run all of the deltas, but the daily invocations +of ctm_rmail and ctm will not take nearly as long. + -
cd where_you_want_your_source_tree_to_be
++This depends on your diskspace, among other factors. Since ctm doesn't +yet deal with files which have been modified outside of the ctm process, +the "better" choice is probably the cvs-tree. Then you can check out +your working source tree from your cvs-tree, and keep your local mods +in your source tree, leaving only ctm to touch your cvs tree. -
ctm -v -v /where_your_ctm_deltas_are_stored/OpenBSD-src.*
-+The drawback, however, is the amount of diskspace it takes. A checked-out +source tree takes about 250MB or so, but if you have your own cvs tree you +need 370MB or so for it, plus another 250MB for the checked out tree. -
or
++This doesn't count the 100MB or more you will need to do a build (depending +on the architecture). -
cd where_you_want_your_cvs_tree_to_be
++If you just get the source tree, you will need to deal with local +modifications. One way to do this is to use the union filesystem, +although there have been reports that the union filesystem can be +unstable if both the upper and lower layers reside on the same physical +filesystem. If you place your upper and lower layers on separate filesytems +you should have no problems. A sample of this is as follows: -
ctm -v -v /where_your_ctm_deltas_are_stored/OpenBSD-cvs.*
-
+Suppose your ctm-updated tree is in /usr/src-ctm, and your real
+source tree, the one you make your modifications to and do your builds from,
+is in /usr/src. /usr/src should be initially an empty
+directory. The following command will set up the union mount:
+
+
+ mount -t union -o -b /usr/src-ctm /usr/src
+
+
+Modifications made to files in /usr/src will become a file contained within
+/usr/src, hiding the one in src-ctm. If changes are made via ctm to the
+underlying src-ctm tree, those changes will not be seen if there is
+a file in the upper layer hiding it.
-
+You should periodically unmount the
+union and search for files which are local to the union filesystem.
+
+
+ umount /usr/src
+ find /usr/src -type f
+
+
+The commands ls -W and rm -W will be useful too, as objects
+named "whiteouts" in /usr/src will also hide files in src-ctm.
-
+If you get the cvs-tree, you can use the "cvs checkout" command to check +out a source tree from it, and each time you update with ctm you can use +the "cvs update" command to update your source tree. -
this simply depends on your diskspace - the better is the cvs-tree - -because you can make modifications to the local checked out copy (ctm can't -yet handle modifications in files it want to update) - but the drawback -is a _lot_ of diskspace - you need currently ~ 240 mbyte for the full cvs-tree -and ~ 200 mbyte for the checked out source tree plus ~ 100 mbyte for the -obj files while "make build" if you have enough space then go -for the cvs-tree - then you simply have to check out a local copy of the -source tree after the first ctm -v -v command using cd /usr cvs -q checkout --PA src and after each new applied ctm relative delta you have to run cd -/usr cvs -q update -PAd src to get your local copy up to date if you don't -have enough space so you can use ctm for getting the checked out copy of -the source tree - but then you have to think about the handling of local -modifications - at this point someone from the NetBSD people is using a -mixture of null and union mounts and some scripts for doing this - if i -remember right it was something like this /usr/src-local is null mounted -to /usr/src - /usr/src-ctm is union mounted to /usr/src so you have all -local modifications in /usr/src-local and you have to run a script which -does something like for all files in /usr/src-local diff them against the -/usr/src-ctm versions and apply this patch to a fresh ctm applied /usr/src-ctm -tree mounted in the above way against a fresh /usr/src-local directory -the union mount of /usr/src-ctm guaranties that the /usr/src-ctm tree is -not modified which is very importand for the operation of ctm all this -is just a rough idea - all in all - it is doable because someone from the -NetBSD people is definitely doing it in a way close to this one
+i will call this now more than a "public beta" state - i'm -using ctm now for more than two months to stay up to date with the OpenBSD -cvs-tree without any problems - and also the FreeBSD people use ctm very -extensively for years know without any major problems i think (i also use -ctm for FreeBSD now for about half a year without any problems) so i think -you really can trust ctm - in the last weeks also some other people used -it and i haven't heard aboutany problems so far
+Ctm has been in use for over a year for OpenBSD, and for FreeBSD for a +number of years. Ctm is quite reliable and stable. -here :-) - but you can take all the information from FreeBSD and you -have the man-pages for the ctm-programs in the ctm source-package there -are some informations about the use and ideas of ctm in the FreeBSD handbook -- which you will find under http://www.FreeBSD.org/handbook/ctm.html
+If you have problems with ctm, a good place to start is the FreeBSD +handbook: -if you have problems with ctm you may also ask me - i'll try to help -you as far as i can and as far as i have enough time (which is a big problem -in the moment)
+ -... and decided to use ctm from now on - here's the summary of adresses: -mailinglists:
++You can also contact the OpenBSD mailing lists or myself if you have +difficulties with ctm, although my free time tends to be rather limited. -
+Summary: -
-
ftp server:
++I will make any important notes and announcements about ctm in: +
there you'll find the deltas and the sources to ctm (ctm.tar.gz - simply -put it into /usr/src/usr.sbin and it should compile fine under OpenBSD)
++NOTE: If you use ctm for OpenBSD, please send me email so I +know how many people are using it! -
i'll also make any importnat notes and announcements about ctm in
+and the big ones in
+and pleeese - send me a mail if you use ctm for OpenBSD so that i can -see how many people are using it !
++Good luck! -
+t -
... go to:
+SO - GOOD LUCK WITH CTM FOR OpenBSD wishes
- -t
- -Last -modified: Mon Oct 28 22:24:34 MET
++ + + $Id: ctm.html,v 1.5 1997/09/04 21:57:18 flipk Exp $ +